Yeah, I was just about to post the inverted question, but you beat me to it.
I flailed around in the first couple years of undergrad, and ended up choosing a career in research biology, and it doesn’t pay shit. As a tech and now grad student, my pay check is about 2x full-time minimum wage. After getting a PhD, I will qualify for jobs that pay about 3x minimum wage. Only the luckiest of the best of the best (high-ranked professors at top-ten universities) will get six-figure incomes.
Still, I get enough money to be comfortable, and I know a lot of people with liberal arts degrees that are struggling to get any kind of job at all. And most of the time I think “someone will pay me to play in lab? Score!” But it’s easy to envy my high school peers who are now engineers, programmers, doctors, and/or lawyers…
I’m smart, but I lack motivation.
I got my Ph.D. in mechanical engineering, and I earn good money doing what I do. A couple of other people in my office - also Ph.D. M.E.'s - have advanced to management positions and are earning considerably more money than I am. I could probably do the same, were I sufficiently motivated to learn about management issues and develop the thick skin that is sometimes required by managerial work. But I’m not sufficiently motivated. I like what I do, and I don’t think I’d like management work.
I also have a small manufacturing business that I run from my home. Boosts my gross income by about 15 percent. Were I sufficiently motivated, I might endeavor to learn about entrepreneurial issues and seek to expand my business by selling my product at relevant expos and retail outlets. But I’m not sufficiently motivated. I like making my product and selling it over the internet, and having to manage a much larger operation with more precision (possibly involving taking on employees) sounds like a lot of the kind of work I wouldn’t enjoy.
Instead of seeking huge incomes, my wife and I have opted to live on our merely robust incomes and save/invest aggressively. Our goal isn’t to become “rich” (whatever that is), but instead we seek financial security - the knowledge that we don’t have to worry about losing the house if one of us somehow ends up unemployed for several years, and the knowledge that we will be able to live well when we retire.
Because he makes bad hiring decisions.
See that’s different from the engineers, programmers, doctors, accountants and/or lawyers some other posters are using as their “rich” benchmark. Both me and my SO are high earners in professional jobs. So we are “rich” by the standards of someone making minimum, or even median wages. But we have to work long, often tedious hours to keep that income.
That’s sort of the Catch 22 for “getting rich”. Unless you are born with some real wealth, typically you need to work your ass off with single-minded purpose over your entire life.
I mean, I guess I “wasn’t motivated enough”–to be rich. I was certainly motivated enough to get a BS degree from a good university, and get a good job with good benefits in a nice area. But I was never motivated to get rich or make a lot of money. Frankly, I like working 40 hours a week and I would not work another 20 hours a week to double my salary, unless it was a super awesome happy funtime job.
Not Lightnin’, but that description fits. I’m an SAP consultant, specializing in three modules (company departments) which rarely get SAP: namely, Quality, Maintenance (internal and for customers) and Production.
To give you an idea:
my last project was a 4-month contract, with the possibility of staying longer. Early in July I was told I wouldn’t continue, and gave a heads-up to several agents. Less than ten days later, I had an offer for a project (Production, for an end-client where I designed the Maintenance part for what’s actually a decade-long project divided in many small bits; Spain and France; until December; given how that end-client works nobody will be staying but the agency is very interested in keeping me booked); I also was in conversations for another project which sounded more interesting so I gave these other guys a couple of extra days before accepting the first contract (Quality; France, Italy and the US; two years’ contract) - these other guys didn’t move fast, so I did accept the first contract. I’ve since received contacts from three other agencies which are subcontracting on finding someone for the second job, after the agency with which I was originally in contact ran out of options… 
hen’s teeth are more common that EU-citizens who know the Quality module, speak English, Itagnolo and some French, and are willing to jump around for two years.
I’ve never cared enough about being rich to work hard enough to achieve it. I would be totally fine if I maintained my current standard of living for the rest of my life.
(ETA: But if you send me money, I’ll take it.)
The White Man is holding us back!
I’m a lazy bastard and decided to major in art. Partially because it was less work. I’m not sure I exactly qualify as ‘smart’. (Although I do have a nice non-art job now, with good benefits.)
I live a comfortable lower-middle-class life (this is British lower middle class - one car, three-bedroom 1,000sq ft house, which is probably breadline by US standards 
) but I would consider myself rich if I were debt-free (including mortgage) and could maintain this life without having to work, or at least only working when I chose to.
I don’t like to take risks. Ya know, put my life’s savings into the next Internet start-up.
I hate conflict, to the point of having given up on managing other people.
I have a strong sense of ethics. Possibly too strong.
And yes, I never caught a break. But I haven’t been hunting very hard for breaks.
I grew up in the seventies when the top tax rate was 70%. I figured there was no sense in being rich if I was going to get taxed at that rate so I chose to be middle class instead.
I was too ethical – too humane – to do the really shitty things that you have to do to become rich in this country. Donald Trump, qed
A lot of truth in that statement.
Why was “I am not smart, but rich” not an option in the poll?
Compared with the rest of the world, I already consider myself rich. But in the U.S., I might consider myself lower-middle class. In my book though, If you’ve got a roof over your head, a job, and money to pay your bills, you’re doing good.
As far as not being ridiculously wealthy, I don’t think it’s a matter of being incredibly intelligent. Drive is not explicitly linked with money and your conscience often directly conflicts with the things you’ll need to do to get vast amounts of money. Most people don’t want it bad enough but thats ok because there are more important things.
What a lucky ducky!
Being smart doesn’t makes you rich; it just makes you a useful source of profit for the rich. I could be the greatest genius in human history, and it wouldn’t make me rich.
What does make you rich is luck, connections, and/or either being a psychopath or willing to act like one. I haven’t had the right sort of luck (like having a rich daddy to hand me his money) to get rich, and I lack the other two factors completely.
Besides the shitty upbringing, this is me. I had a plan when I was 14 and targeted everything toward it, so now I’m senior-level before I’m 30. I do the same things I did in the army, but now they have to pay me what it takes to put up with that shit.
The only rich people I know that don’t work for it are old, retired, rich people. Everyone else works all day and some nights.
Every time you say this, a bunch of rich Dopers offer themselves as counterexamples. Why do you continue to make this claim when it’s been refuted over and over?