I’ve been on their online forums, but I have literally zero experience of the Bay Area rationalist scene or any other. Of course I know about the billionaires, but I thought the answer was going to be that the rationalists come from wealthy families and social circles.

their problem is … [several items omitted] … they can always talk a friend into wiring them another $100,000

Assuming you’re correct about that, I would love an explanation of how they come to have this enviable problem. Is it primarily a matter of social class, or is there some more specific category of origin which produces people who can’t invest or run a business, but never run out of opportunities to keep trying?

Visit his blog and you’ll find he has genuine paranoid delusions (he claims to be “Q from the Qanon movement” and has a post about his ex-wife’s conspiracies against him)

Sounds like a job for RationalWiki

https://rationalwiki.org/wiki/Infrasound