Nah, I got another theory.

Basically, people that tend to be more 'intelligent'/'successful' are better at learning. You optimize learning in a similar fashion to a start-up. By failing fast.

In general I think you tend to hear alot of silly thoughts from very 'intelligent'/'successful' people because they tend to speak their thought often and early (even if they do not have a grasp on it yet). Which leads to quick correction and refinement. Or in other words faster learning.

I agree about being better at learning. Maybe they (we?) tend to sometimes vastly underestimate the difficulty of learning in certain highly complex areas (like medicine) due to past successes learning difficult (but not as difficult) things.

Musk is definitely by all accounts a genius, at least in certain domains. See my other comment about non-transferrability of expertise. I think the reason there are so many genius morons is that people assume their expertise magically transfers, and so they skip doing the work required to gain expertise in a completely different area.

"I can code, so I can reevaluate history and political science." "I can do organic chem really well, so I can read a creationist polemic and dismiss all of geology because it seems to make sense to me."

Aka engineer's disease