> There's lots of enjoyment to be had in learning things that aren't immediately (or even remotely) useful, and there's often a lot of unanticipated utility in learning things that are pursued for pure enjoyment.

I'm not sure what you're arguing against. Enjoyment is utility. But if I would enjoy learning two different things equally, I should pick the one that would also satisfy me in other ways, or the one that would deliver that enjoyment more efficiently, so I can also have time to do something else that I also enjoy.

There's a cost to spending time, that's why people call it spending time.