Youth in Gaming
This attitude isn't a product of hating other games, or even an unwillingness to try something new. It comes, in my experience, from the person's intense love of role playing games in general, and their chosen game in particular. Whatever game they played first or most epitomizes tabletop games for them, and they can't conceive of how something could be a better RPG than what is, to them, the very definition of an RPG.
I can remember playing Dungeons and Dragons on and off in highschool, but never being particularly impressed. It didn't do anything for me and I didn't see the point. But I also remember when I first picked up a copy of the new World of Darkness. I thought "This is it. This is the best game ever. It's so versatile and easy. I can run anything with this!"
And I did. I played werewolf and vampire, but I also ran dungeon crawls, space operas and fairy tales (before changeling or those awesome mirrors supplements came out). I was willing to run anything, so long as I could run it in the World of Darkness.
This kind of attitude can lead to some ridiculous scenarios; I've seen people try to run the Dresden Files in 3.5 DnD, and I've myself run Serenity in nWoD. It isn't that those ridiculous experiences can't be spectacular and fun, but it does limit a person's exposure to all of the amazing things that are out there. If you only ever run one system, you never get to experience the joy of a different kind of play, or a different rhythm of game. As we grow older and our love of gaming grows and matures, we start to explore, first trying to convert different settings to our favorite system, then cautiously trying new systems one by one or piecemeal, then finally allowing ourselves to enjoy the full panoply of games available to us.
This trend is too common to ignore, but after speaking to a few gamers who run the spectrum of years, I'm convinced that it isn't a matter of generation, but of age. I talked to a twelve-year-old girl whose mother brought her to game, and she told me about how she wanted to do a werewolf game with 3.5 DnD, which was the only thing she'd played. I asked her whether or not she'd heard of World of Darkness, to which she responded "yeah, but DnD has already has all the stuff I want!". Talking to that same mother, who is about ten years older than me, she said that she had just heard of Nobilis, and was going to try and learn the system. She had only ever played WoD and DnD, but she was cautiously optimistic, and interested in how a resource-based conflict system would play. After that game, I started talking to one of the regulars, a man in his forties, who excitedly explained the differences and similarities between Mouse Guard and Lady Blackbird.
There are exceptions to this of course. Some people don't get particularly attached to one system or another. Some people are ahead of the curve, and are excited by the prospect of a new game, while others take a deep joy from learning all the crunchy bits of a new system. But as we grow older, those exceptions matter less and less. Not because their willingness to try new games isn't valuable, but because as we become more mature, we start to catch up. My generation is reaching the stage where we're beginning to cautiously poke our heads out of our respective corners and take a good look at what the RPG community has to offer us. And that willingness to expose ourselves to new games, settings and systems can lead to even more ridiculous scenarios; a friend of mine is getting ready to run Inception using hacked Mage rules, and I'm going to be doing a one-off zombie game using Lady Blackbird. The transition from single-system loyalty to multi-game exploration is something I think a lot of us do and have gone through, but like everything else it's a necessary part of growing up. It gives us a stable place to start out from, and a steady foundation from which to build a better RPG community.
I did eventually grow to love DnD, just like I've grown to love so many other games. Since coming to college my repertoire of games has expanded from nWoD and a little 3.5 DnD to include Mouse Guard, GURPS, Lady Blackbird and countless others. I can't say that I don't feel my enthusiasm lag a bit when I'm asked to learn a new system; it's difficult to memorize a whole new set of rules, and I have so many already. And I can't say that I don't heavily favor some systems over others; my generation just got to experience its first major edition war (I like 4E, sue me). But I can say that when someone finally explained how Aspects worked in the Dresden Files RPG, my eyes lit up just like they did when I picked up that first World of Darkness book, and I think that's a step in the right direction.

