You haven't accounted for selection bias there. It is quite likely most people don't find a productive activity fun and it is a much better plan to try and be somewhat wealthy doing something that inspires a neutral feeling rather than poor. Much like the girl you find cute on first glance, if you change your mind later then it'd have been a real mistake to over-commit on first impressions.

If there are 10 people who want to be plumbers but the economy is signalling it needs 20 plumbers then it'd be best if 10 people who don't enjoy plumbing all that much do it for the money. If there are 100 people who want to make a living as an artist and only demand for 1 it'd be better if most of them overruled their instincts and found something more useful to do. Paint as a hobby and live as something else.