I don't know anyone personally that has gone into the video game industry, but from those that I know that wanted to go into the games industry, most of them seem to only play mainstream titles.
But, when you look at it, mainstream titles are mainstream, so more people that only play mainstream titles will become game developers than people that play a lot of or mainly innovative/independent/non-mainstream games.
From what I've noticed, the game developers that like non-mainstream games join together, just like how we have noticed on South Park about how Goth kids, and later Vampire kids, gathered together (but the vampires went to Hot Topic and turned other kids into vampires, just so Comedy Central could sell some Vampire kids T-Shirts there).
Anyways, games like Okami, Ico, and Madworld show that the percentage of non-mainstream games are probably larger than the percentage of people that want to play the non-mainstream games.
The people that I know that wanted to become game developers seemed to be xenophobic, but it may have just them being Nintendo fanboys.