Could you elaborate on how Katja's idea in the OB post might be used here? To me, it seems like it supports the OP (quite nicely, actually). In particular, Elon Musk shows that Tony-Stark-ness (as you've correctly defined it) is pretty darn visible. If there were more Tony Stark's out there, I'm now more likely to expect expect that I would have heard about them in the same way I've heard about Musk. This increases my confidence that there are not many Tony Starks compared to my pre-Musk assessment.

And then, of course, the question is: with so many billionaires out there, why?