Yes, this is indeed a rather pervasive stereotype on music boards. But, let's be honest and counter with our own stereotype: aren't all music nerds really strongly elitist at heart anyway?
*Sigh*.
Those stereotypes, like any, may have a small foundation in truth. There is a sub-section of gamers focusing uniquely on a single genre (and pushing it on others they come in contact with). There is a sub-section of people who make/write/listen to music on a certain level that are highly elitist. However, neither of those sub-sections mean the group as a whole is like that and does that. Speaking for myself, as both a music and a game nerd, I like to think I'm not a horrible elitist who frowns on everything that isn't complex technically or emotionally (even if I will not like everything, but eh, everyone else's choice what they want to listen to, wasn't all made for me anyway), and as a gamer, while, yes, I do listen to game soundtracks (and there are some good ones out there, honestly, even if this is one of those things the music community doesn't agree on with me

), I also listen to baroque, classical music, jazz, musical, some pop, some folk, some rock, some techno and various forms of metal.
Limiting yourself musically is like limiting yourself to playing one game genre only. Sure, you may enjoy that genre more than most others, but you might just miss that gem of a game/song in another genre that is capable of giving you some enjoyment elsewhere.