Rutgers is prestigious? It’s the state university in New Jersey.
When did it become a given that parents would pay for their child's (children's) college attendance?
Eh, it’s been a few years. Details, details! 
To be fair, I think that… other than Columbia… Rutgers was the most highly thought of among her selections.
While I was in college I worked summers and managed to get a job at the school as a lab assistant, which helped me make enough to supplement my student loan. I was a regular visitor to the financial aid office, which would help me look for any grants for which I might qualify; I don’t know what it’s like now, but there was a whole book full of them, some of which had interesting qualifications (I vaguely remember getting a few hundred dollars because of some minor skill I had picked up).
My junior year I was a little short of cash and my dad loaned me $500. It was understood that I would pay him back after I graduated and found a job. It wasn’t until graduation day that he told me that I didn’t have to pay him back, but if I hadn’t graduated he would have expected to be repaid.
It does seem that way. I think it’s short-sighted. College is about becoming a responsible adult. I think Lesson #1 is making a responsible college choice.
I went to a prestigious college that my parents paid for, my wife went to a state college on a full ride. She has a stronger work ethic and better job - I don’t see that our choice of college had a ton of effect on those outcomes.
What we’re doing for our three kids is contributing the maximum amount per year into a 529 (“max” being the amount that brings us the max tax benefit), and they’ll get that for college from us. It should be plenty enough to pay for state college (which are very good schools, IMO). If they want to go to a private school, that’s on them. And we will work to make sure they’re aware of the costs and perceived benefits of that decision.
My lovely wife went to a state school, while I went to a private college. My education was far better, and a better match for me. She was far enough away from home that she couldn’t live there; my parents suggested that if I didn’t get into my first choice college, they wouldn’t approve my second (a combined BA/MA program) because it was too close to home and it wouldn’t be cost effective, so I’d have to go to the state university. My response was, then why did you permit me to apply to my second choice? (Not well understanding college admissions, they didn’t allow me to apply to comparator schools because "If your first choice doesn’t let you in, the others won’t either.) My response was also, if I don’t get into my first choice and you don’t allow my second, I’ll get a job and move out, because like hell I’m going to a school with 39,000 undergrads when I want to go to a school with under 1,000 students. I should perhaps mention that by 16, I was doing my friends’ English homework at said state university and obtaining excellent grades for them.
In 1990-94 working 1200 hours at $5 an hour paid for 75% of the total cost of attendance at the top 20 engineering school my brother and sister attended. In state, state school.
Now the same school costs $40k in state and jobs around campus pay $10/hour. Plus you are required to do way more than attend class and do homework now. There are all manner of “clinics” because the classes are huge and the clinics are the only way to get any questions answered. The coursework is a lot more demanding as well. It’s more difficult to hold down a 15 hour a week job during term time.
I think the numbers would need to broken down by parental SES.
For upper SES parents who will at some point be leaving an estate, paying for college is a very efficient means of intergenerational transfer of wealth.
I’m glad that my premise is not 100% correct. 
Happy to hear counter-examples.
I have a couple of children - graduated 2020 and '23 - and their experiences and those of their classmates may be relevant.
tl;dr - Kids these days are a very mixed bag; a lot of them are being very realistic about their school costs and some of them are shouldering the load themselves.
Since the year SunSon was born, we’ve been putting some money into a 529 plan for their college educations. Actually, now that I think of it, we put in a whole bunch early and then added to it in dribs and drabs thereafter. We’ve discussed college with the kids, with a few salient points: it’s likely they will want to go to college, at least to earn the credential, but there are plenty of things to do that don’t require a degree; we want to get them through their bachelors degrees without debt; we’re not writing a blank check - if college in general or their specific degree program starts to become something they don’t want to do, and their grades reflect that, we can look at something else or transfer to a different college or program.
SunSon graduated in 2020, into the teeth of the pandemic. He took a college readiness class in 11th grade, one assignment of which was to apply for a scholarship. He promptly got the one he applied for, which pays about 60% of his tuition. He’s lived at home all three years (and will do so again next year) and takes a five mile bus ride to school. He’s the beneficiary of our 529, the gains of which - because of the scholarship - has almost kept pace with our withdrawals. He’s thinking he’ll start Masters level classes while he’s finishing his Bachelors, and he’s already aware that he’ll need to pay for his own tuition when he switches to grad level coursework (though he’ll be able to stay at home).
I don’t know a lot about his friends’ college funding. At least one of his friends took a gap year due to a legal dispute between her parents and the local university. Another of his friends came out as trans during the pandemic and ended up breaking with her family over it; she’s working full time and looking at the local community college for her start at education - I have the feeling she will have a long road. Another friend, whose parents divorced a while back, is working on the same degree he is, but started at community college - it’s an endorsed degree path, so the credits will transfer over.
SunLass graduated last month and will be headed to a CUNY school this fall, so the major expense for us is not tuition and books but rather rent. We will do a 529 beneficiary transfer over to her next summer, which - if she gains in-state residency status at some point - may be enough to pay the rest of her tuition. Our out-of-pocket expenses for a year of her school will exceed what we spend for SunSon’s four years; I’ve talked to him about this, and he is grateful that we were able to fund his degree rather than being resentful that we’ll be spending a whole lot more on his sister.
SunLass’s friends… are kind of a special case, because many of them were on her club volleyball team and have been angling for years for college scholarships. I think that six of the nine senior members of her club team ended up with scholarships; two others went division III, so no athletic scholarships are allowed, and the last will try to walk-on at her division I school. Of course, the $$ involved in club volleyball can be thought of as an early investment with the hope of paying off in a scholarship.
I was very surprised at the number (60% or more, I think?) of her high-school class peers who are headed for the local university rather than going out of state to school. I suspect that even fairly generous scholarships aren’t enough to offset the value differential, and that a lot of these students may be thinking of grad school as their opportunity to travel for an education.
Until the mid-century the only kids who went to college were from wealthy families or got major scholarships. When I finished HS in 1954, a year’s tuition at Penn was $700 (an inflation calculator gives that about $7000 today) while it now approaches $60,000. Anyway, my family certainly didn’t have $700, but if they did, they certainly felt obligated to use it to pay my tuition.
When my kids went to college in the 80s and 90s, tuition had started to skyrocket, but with a combination of scholarships, loans, and essentially all my wife’s earnings, we managed. We eventually paid off the loans since we considered college our obligation.
But to contrast this, a neighbor’s daughter took advantage of her father’s faculty position to pay only half the tuition. That half tuition was only about C$800, but they added it to her father’s salary and he paid taxes on it. (I should mention that in Canada, tuition is tax deductible but only to the student and the decduction cannot be transferred to the parents or carried over.) Anyway, her father insisted she pay him back the extra tax he had to pay. So I guess it varies. But I don’t think it varies with time as suggested in the OP.
My parents couldn’t afford to send me to college, so I joined the USAF and after I got out I went to college on the G.I. Bill.
I was going to agree with this, but when I started writing I realized how much more complicated and nuanced the history is.
The earliest colleges were intended to train ministers, in the tradition of Cambridge and Oxford. Unlike them, students lived frugally and worked to pay their way. By the Revolution they had evolved to attract the sons of elites but also bright outside strivers like Alexander Hamilton. But one of the weirdnesses of American culture was that anyone could start a “college”. Literally thousands of small colleges were founded, most of them either religious or “normal” schools, to graduate teachers. The sons of the elites still went off to Harvard, but they were vastly outnumbered by ordinary kids working their way through school.
Additionally, every state created a state college, which grew to be university systems. Land grant universities (known as A&Ms - Agriculture and Mechanical schools: think Texas A&M) were based on federal grants and inteneded to teach practical skills. Good ol’ State U was the rival to the liberal arts U of, especially in the midwest: University of Iowa vs. Iowa State University, e.g. “State” didn’t get as many elites.
By the end of the 19th century most if not all state universities were co-ed. The Ivy League famously was not. But the Ivy League had huge internal rifts between the elites and the smart outsiders, who had to work to pay tuition and were kept out of the clubs that fostered networking. For all this access, only about 5% of the cohort got a degree in any year until post-WWII when the GI Bill tripled that number essentially overnight. It was those parents who created the expectation that their kids would go to college paid for, in those days, fairly easily by middle class families.
When you talk about college/university the default picture is of an Ivy or their smaller equivalents. (Though Cornell, a private college, is actually New York’s land grant university and its Ag School is a big deal. Fifty states, fifty exceptions.) But probably 100 times as many students go to state university systems, which include research universities, liberal arts universities, technical colleges, community colleges, and specialized schools, plus graduate schools of all kinds. The vast majority of attendees get financial aid. Parents mostly don’t pay for college: they pay what’s left from the total. I went to college solely because I got a full scholarship. Tuition was raised sophomore year; my aid wasn’t. I’ve never forgiven them.
This tiered system of elite private schools and state schools and thousands of little private schools doesn’t have a parallel that I’m aware of. But it worked extremely well until recently, when the expectations and needs of society started to clash with the realities of what colleges could do.
Thanks for the deep dive
My bold.
This is exactly the thing I’m asking about. Why did y’all consider it your obligation?
In addition to everything you said, I attended a residential college, with dormitories, fraternities, etc, which is I think what many picture when they think of college. But I believe the majority of students attend what used to be called a commuter school and many schools have no dorms.
Not @Hari_Seldon , but I consider raising my kids to self sufficiency to be my responsibility.
Legally my parents could have told me to bugger off at age 18, and I could have ignored anything they said after that age.
Most parents and children prefer not to do that, assuming they each have the wherewithal to financially support and benefit from further education.
And that self-sufficiency to begin after college graduation?
I think my parents saw it as beginning before college. College was extra. Above and beyond.
Yes, now… but not always the case.
In our case largely because our parents had paid for ours.
Family of origins values on both of our sides was that parents pay for education as best they can.
Children having a chance to be as highly and well educated as possible is more important than most other uses for our money (after basic needs are met).
I was shocked when I got into a conversation with our now past CFO, well compensated in that position, who shared about his kids loans for college and in same breath his big trips.
Yes. My grandparents were immigrants and getting their kids an education was seen as the most important thing they had to do. This was the same for my parents, the same for my wife and I.
This doesn’t mean I didn’t have jobs all the way through high school and university, but I left university without owing any money. This enabled me to go out on my own and start a business. I hope to give my kids the tools to succeed in the same way.