Even in that situation, while that cuts the number down I'd still put good money on there being a lot more entrepreneurs who had one great success and then cash

Even in that situation, while that cuts the number down I'd still put good money on there being a lot more entrepreneurs who had one great success and then cashed out compared to the number who are "serial entrepreneurs". I think there's still SV-bubble (not economic bubble, but bubble in the social isolation sense) logic going on there in assuming the majority are serial. Of course, I have no data to back this up (but neither does the other viewpoint -- a list of 8 or so guys is hardly a good argument for that side).