People just need to take responsibility and make better decisions when they purchase a house. 
Or one might ask who knows more about what it takes to make a good solid house? An individual buyer? The builder? A group, presumably acting with input from buyers and builders, considering economics and trends in building technology?
Building practices are influenced by convention, expense, available materials, and development of code. There seem to be periods with more bad construction, but generally as building code has developed build quality has improved. Materials change as what was once plentiful becomes harder to get and promising new materials become available.
The seventies saw the introduction of fibreboard sheathing (“Buffalo board”) which made sense for its water and pest resistance but was terrible for shear and puncture strength. The main purpose of sheathing in wood frame construction is shear strength so that is a major failure. Longer lengths of large size dimensional lumber became increasingly expensive so you see a lot of laminated 2x10 or 2x8 beams cobbled together from short lengths. There are a lot of sagging beams because of this. Most beams are now made with engineered lumber such as LVLs which are far superior.
Douglas Fir lumber is very strong and was used a lot in framing but became more expensive and was largely replaced with spruce through the seventies. Fir is very strong but tends to split and twist much more than Spruce. It is a great material for beams but I have seen a lot of twisted fir studs. Subfloor construction changed from Ship lap fir, and God forbid spaced 1x6 fir which is absolutely terrible, to plywood which is much better.
Definitely some poor building practices in the seventies but there were improvement over earlier practices also.
I have a 1970’s house and nothing particularly stands out as crappy about it. Good quality wood studs from what I’ve seen, real plywood, nice hardwood floors and trim. I guess the worst parts are some of the older single-pane windows and the masonite siding on the second story.
I specifically look for late 70s homes for a variety of reasons;
Hopefully no lead paint issues.
Hopefully no asbestoses issues.
Romex wiring with a traditional breaker box rather than knob and tube and fuses (or aluminum??)
Copper pipes
No plaster and lath
Standard sizes for just about everything.
My house was built in 1934. (There have been three additions over the decades.) It’s the only place I’ve lived in that had a fuse box. And knob-and-tube wiring. I get my car insurance through USAA, but they would not insure the house because of the wiring. Last Summer the fuse box started humming. That’s not good. After living here for 13½ years, it was time to replace the bloody thing. In the process, the electrician discovered that the entire kitchen was on one circuit. I’d had a 30 amp fuse, so everything worked – but the wiring was definitely unsafe with it. The kitchen had to be rewired with conduit. There are now two circuits for the kitchen, plus one for the microwave oven (three circuits total), and the refrigerator has a dedicated outlet. It looks like the front bedroom, a later addition to the house, has conduit, which is a good thing. But expensive. Mrs. L.A. paid $1,900 for the job, but my share was $3,500. And I’d already ordered two new front windows for the house to replace the paper-thin single-pane one ($1,500). And in Spring I put about $2,000 into car repairs. And before the house repairs, I had to buy airline tickets for about two kilobucks. In August I learned my job is in jeopardy because the president of the company is looking to cut costs. I’d be in much better shape, were it not for this old house.
During the summers of 75 and 76 I worked for a plumbing company that plumbed new homes in housing plans being built by Crawford Construction. I was in Highschool! Technically I was a “plumber’s helper” carrying stuff between the house and our van. In reality, I was a plumber. I installed copper water lines, pvc waste lines, and gas lines! I was taught everything I needed to know as we went along.
If an inspector or other unknown person drove into the plan where we were working, whoever noticed first would run to their van and beep the horn. Workers like me would drop whatever they were doing and walk outside.
My impression at the time was that this was how things were done.
ETA: I made minimum wage doing plumbing. It was difficult work. In 77 I got a job manning the booth at a self-serve gas station (55.9 a gallon) where the job was easy and I made better money.
My condo was built in 1987. Near as I can figure, the plumbers were trainees stoned out of their minds.
And it has been proven the building inspector was Ray Charles, with three hands.
How the frack does one plume a furnace backwards?
Five people died of carbon monoxide poisoning in their rented house. The homeowner, 73-year-old retired firefighter Darrell Atkinson, had attempted to fix the furnace himself rather than to hire a professional. He wanted to save money. He was arrested, and asked how much his bond would be. When he was told $20,000, he went to a coffee can in his kitchen and took out $20,000 before being taken to the station.
Atkinson later committed suicide by carbon monoxide poisoning.
From this link [case changed for readability]:
Totally anecdotal: Mom & Dad divorced in '72, and Mom was able (financially) to get a small-ish new-built 3 bedroom/1bath house in a new development in our small town/suburb of the St. Louis East Metro.
The roof leaked, the basement flooded (the land was not graded properly!), the foundation subsided, and that was in the first couple of years. I recollect ongoing improvements/corrections into the early 80’s.
A class action lawsuit against the contractor & realtor defrayed some of the costs, but homeowners were still stuck with substantial repair bills for things that should never have been a problem in properly constructed new homes.
Just my 2-cents.