Perhaps the premise, that smart people maximize income, is incorrect.

Fair enough. Let's imagine for a moment that some "smart" people don't maximise income. My question then is: why don't they use those extra 40 hours to optimise whatever makes them tick (solving global problems, building their own biz, creating great open source software) instead of being paid truck driver rates making somebody else rich? That still doesn't seem very smart.

I just left a low paying 80 hour a week job for a high paying 40 hour a week job with that exact logic - I can do what makes me tick in my spare time.

As it turns out, that's a lot harder than you're making it sound. I absolutely loved my previous job, where I was building a quality product that I knew my customers would enjoy. There were some leadership-related issues that came up there, so I thought I could build a product on my own in my extra 40 hours a week. Now I have no product (or product ideas) and no customers. Instead I spend my time networking with people who might have those two things. I feel like I lost out, even though I'm getting higher pay.

Maybe they're not as good as they think?

https://en.m.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effec...

That is probably true in some cases.

You need to define work. Is the amount of time I spend learning a new framework/language also work? By that definition none of us are very smart.

If you mean to say work as defined by the specified project you need to determine if there is something else they are seeking that provides worth. Do they want to be seen as necessary? Do they need to learn the whole system/program to have a sense of job security. Some people love the whole idea of saying they have spent more time than anyone else working on the program/app at hand. It's BS I know but for the non technical manager those are the sweetest words.

It's not easy to make utilitarian calculations based solely off monetary units divided by time. Exchange value is never easy to determine. For you it may be easy to find another job that pays same or more for same monetary value divided by time. For others, it may not be so easy.

They don't minimize amount of work they do, because they greatly enjoy the work, and get great pleasure from the process of programming.

So why not work a 40 hour job and then spend 40 hours working on your own stuff instead? That not only doubles your hour rate but also makes it possible for you to create whatever makes you excited (your own biz/open source software/whatever). Or (alternatively) simply have a life beyond work.

Believe it or not, some people are excited by their work, and believe it's the most important thing they're doing.

Not everyone is a slave to a job they hate, which seems to be your perspective here.