Well, to be fair and balanced, now I’ll vent some bile at some non-D&D games. I own literally thousands of RPG products and will play nearly anything, but there are three pretty major games/game systems that I’ve avoided like the plague. And the reason why boils down to the general player base for those games. Some games have better or worse mechanics etc. – FUDGE dice are the worst idea ever – but that doesn’t spur active avoidance in me. I’ll go as crunchy as GURPS or as light as a pure storytelling game. But here are the three big problems for me…
World of Darkness. I am happy there’s a game for out there for goths experimenting with their bisexuality but that’s not me. I don’t want to hear a cute little story about how your cat Crowley was trying to drink from the chalice while you were trying to get your pre-game blessing done (true story). I avoid life situations that would tend to get you in jail/in trouble and the average WoD group rings all kinds of alarm bells for me. (I’m sure many WoD players don’t fit this mold, but the crowd of black-and-hat-wearing teens choking the sidewalks outside every con I’ve ever been to do. And why always outside the con out on the street? Not enough allowance for actual admission? Clove cigarette smoking not allowed inside? What?)
True story. I was playing a pick-up game of Deadlands in some city I was travelling through, in a game store. (I try to avoid gaming in game stores but that’s how this came to pass.) A girl walks in, an obviously underage hottie. The crowd of guys leers and hoots quietly to themselves. But one local says “Ah, forget it, she’s a lesbian I think, I saw her making out with some girl.” I turn and take a look – ripped fishnets, heavy eyeshadow, black clothing. “Nah, she’s bisexual.” Everyone looks at me. “What makes you say that?” “Well, she plays Vampire doesn’t she?” “Yeah, she does, how did you know?” “So, about that. <I draw a card and return to playing Deadlands>”
Palladium/RIFTS. High on the “spazzy kids” factor (and uber closed, even for a closed game – before the OGL and official open gaming I hated Palladium for that.) Of course, I guess many of the spazzy kids have aged, but my initial Palladium runins were in the 80’s and first impressions die hard. And really, I never did like Heavy Metal or Wizards all that much, which seem to be one of the key insiprations for this. Also, and again just in my experience, but every RIFTS player I’ve ever met has at some point proudly proclaimed their current or past drug use. (true life quote: “Sorry I’m acting weird guys, but I’m sweating out the chemicals! That pitcher of shroom tea really did a number on me!”
Traveller. Grumpy old school physics wonks. Maybe they’ve been dying off, which is welcome, as I have played a little d20 Traveller (fun except the d20 adaptation stinks) and am looking forward to Mongoose Traveller. The “grognard squad” has gotten quieter over time. I have a degree in electrical engineering, I don’t need some guy whose only claim to higher education is mini painting lecturing me on “realistic space travel.”
Role-playing games are inherenty social activities, and the makeup of the involved gamers and the behavior of that game’s community is an important factor for me, moreso than game mechanics or the like.
A smaller example – I decided not to try out The Riddle of Steel, an otherwise promising new indie game that had gotten some awards. Why? Because from what I could tell on RPG.net, all the TRoS boosters were total assmasters. In any review or forum thread where TRoS was discussed, “the faithful” would descend and batter anyone into submission who did not accept that it was the Best Game Ever ™. (go search on RPG.net for “Riddle of Steel,” and I guarantee you’ll find examples of that in the first few results.)
Geek Related 
Oh, how do I respond let me count the ways. Let’s go in reverse order.
Traveller. Played it. Ran it. Of course, that was way back when there wasn’t any other sci-fi RPG’s out there. I’m talking even before Star Frontiers. The universe background has grown immensely since then and there are enough variations based on different rules systems to still make it viable but it wouldn’t be one of my main picks for game to play or run.
Rifts: Ran it. I’ve always thought that Rifts was a good concept linked up to a crappy game system. Let’s face it Palladium is just a D&D knock off and not a very good one at that. At the time that I ran it all the players were all power gamers and loved the big flashy guns. They liked it until I started hitting them with things that attacked their soft juicy brain meats.
World of Darkness: Played it. Ran it. Finally liked it after not having a moody poser GM. Longest rant because I both agree and disagree with you. Back when Vampire first came all it did was attract the Anne Rice fans. So what did you get? A bunch of whiny goths. But since then the genre of urban fantasy has massively grown and diversified. Now you have the works of authors like Jim Butcher or Simon R Green. You have movies, TV shows and comic books like Blade, Underworld, Hellboy, Buffy/Angel, G Vs E, Nightwatch and Supernatural just to name a few off the top of my head. Basically, a lot of people who are gravitating towards the game are inspired more by the recent sources (which have a much more action oriented and RPG familiar tone) rather than a prissy French vampire. There are still people who play the game like that but they going by the way side. I remember the White Wolf message boards when it was announced that McWoD was going to be d20. You could tell the whiny goths right away. They were afraid that a bunch of D&D players were going to beat them up and steal their lunch money. Everybody else was pretty much, “Eh, just another game,” or “Wow, that’s pretty cool.” Thinking that all WoD players are bisexual whiny goths is like thinking that all D&D players are fat losers who still live in their parents basements. And I’m both. That is a WoD and D&D player NOT a fat bisexual whiny goth loser who still lives in his parents basement.
Yeah, I know a lot of my impressions are mired in the ’80s… It’s hard to tell when things change, though. You & your group were the first “normal” people I had witnessed playing WoD, hard to tell if you’re an aberration or not 😛