Funny, the NYC Meetup (today) is going to touch on this topic ('cause I've been thinking about it). It's one of the "ways rationalists can make money", IMO.
I agree, it does seem like a great untapped potential for a rationalist community. The obvious question is, does being a rationalist make you a better founder of a startup? Or, more relevant here, does being a rationalist of LessWrong stripes make you a better founder?
When it comes to programming prowess, I doubt rationality confers much benefit. But when it comes to the psychological steel needed to forge a startup: dealing with uncertainty, sunk costs, investors, founder feuds, etc... I think a black belt in rationality could be a hell of a weapon!
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