Some people with high IQ are smart enough to say "I want to be a cab driver", and do it. They probably are happier in their jobs, than many others who just do whatever "is expected" of them.
Yes, and when what's expected is starting a start-up, you get HN crowd, where someone who never tried like me often feels that starting a start-up is really overrated here. For instance, I wouldn't bet a lot on Larry Page or Mark Zuckerberg being much happier in their lives than your average immigrant taxi driver.