One other tricky scenario: if someone is really invested in a particular field of programming, like crypto, they may be in a situation where any work they do outside of their employment is at risk of having their employers claim it as a work product or as a violation of a non-compete contract.

I've met several very brilliant programmers in my day that liked to work long, super-focused days on the problems they were presented with at work and then would go home and do anything but look at a computer. I'd be hesitant to suggest they had any lack of love for their chosen profession.