Evil Alpaca said:
Didn't movie Bob do a segment on something like this with D&D nerds versus Sports fans?
The best reason I can think of is that Halo is in a made up universe so it is dismissed as juvenile while Black Ops is the more "mature and edgy" game that talks about real events and therefore is more of an "adult" game. I personally think its hilarious that a super soldier set in the Cold War is somehow more unrealistic than one set in the far future.
Of course, sci-fi/fantasy fans would never look down upon sports fans for their chosen form of entertainment... like Movie Bob does on a fairly regular basis, like dismissing first-person shooter fans as immature jocks
There's a lot of snobbery going both ways. In comic fandom, it's pretty easy to find comic fans who treat the super-hero stuff with a bit of scorn (they're the ones who are quick to point out that they like stuff like Preacher, Sandman, or Scott Pilgrim)... then head over to certain corners of the Internet and die-hard super-hero fans are ridiculing fans of those books, accusing them of self-loathing.
I was once accused by a woman with a serious soap opera obsession of "living in a fantasy world" because I spent a good portion of my free time reading science fiction and comics (among other things). And she was the one who talked about fictional characters as if they were real people.
Even among sci-fi fans, you'll see it spring up. When Avatar came out, hard core sci-fi fans branded the movie's fans "Avatards" because they're painting themselves blue and taking the whole thing a bit too seriously.... but going to see the new Harry Potter in Wizard robes or a Star Wars movie in Stormtrooper armor were perfectly acceptable.
As Robert Heinlein once said, "man is not a rational animal, he is a rationalizing animal". We are littered with logical contradictions that we absolutely refuse to see.