Eh, there's plenty of ugly looking founders out there (Certainly circa 1980's Bill Gates was no ones idea of a cover-model).
Plus I suspect there's a confounding factor in there. Here's a picture of Musk and Thiel[1] around the time Paypal was started. Its pretty clear that personal trainers, chefs, tailored clothing and whatever the hell treatment Musk got for his hair can go along way to making successful people better looking than they were when they first started earning the big bucks.
[1]https://cdn.shopify.com/s/files/1/0196/5170/files/uzn_146193...