Tim Dillon said summarized it pretty well - can't remember or find the exact quote. Something to the effect of:

"Look around at all these things I have - how could I be wrong when I have so much?"

And that's how you get the Andreessen's and Musk's of the world stating these nonsensical things as truth. In their minds, financial success is the ultimate yardstick. The fact that they have so much wealth is a testament that their way of thinking is always right.

You don't need to look very hard to see this is what they really believe. Elon has done extremely silly things like claiming he was the best Path of Exile player in the world because he paid several people grind his account to a high-level. Having enough money to pay someone to play the game for you, is the same as being good at the game, in his mind.