Dalton Caldwell and Michael Seibel have talked about a similar phenomenon applied to YC and startups in general. It seems that early on it was a weird and nonconformist career move, but now it has become something that is done out of the same conforming impulse that going to school or working at a big firm mean to an individual in society.

Before when you had a startup it was because you had a passion and an idea.

Now the passion is the idea of the startup and a big exit.

Totally different groups of people.