[pessimizer]

Second-order survivorship bias. The vast majority of delusional megalomaniacs are abject failures (at least when compared to their own ambitions), and the number of them who live in the gutter and eat out of trashcans is at least four orders of magnitude higher than the number who find success.

People who find success often become delusional megalomaniacs after achieving that success, when they see their success as evidence of their own greatness, not before. The idea that it's the megalomania (or a black turtleneck) that makes you successful, or even makes you brave enough to attempt the things that might make you successful, is an illusion.

A defining commonality of delusional megalomaniacs is their destructiveness and their danger to the people around them and themselves. Worse, they tend to attract followers who both amplify the reach of that destructiveness and who create an echo chamber that reflects back and amplifies the megalomania that attracted them, making the situation worse.

> That sort of delusional megalomania seems to be a necessary motive force for tackling hard, risky problems.

There's no evidence of this. Everything difficult was not solved by assholes, and Zuckerberg didn't solve anything difficult.