Why sports fandom is more socially acceptable than media/sf/f fandom

A couple of weeks ago, I posted about Jimmy Mac's reply to Roger Ebert's review of Fanboys (now expanding to 10 more cities this week). I asked the rhetorical question on why sports fans get a pass while we're labelled as geeky, nerdy no-lifers. Remember that Jimmy Fallon movie with Drew Barrymore where he plays a diehard Red Sox fan? Now I know from personal experience that Red Sox fans come in only one flavor: obsessed. The movie reflects that. But in the end, is it Fallon who's expected to grow up and leave the bleachers behind for Barrymore, who plays a hardworking career girl? No, of course not! You know if Fallon was a Trek fan, a SW fan, or a comics fan, he would be the one to surrender his life for a life of proper mundania.

Why is that? I've mentioned some theories to one of the replies. Here they are in greater detail:

( Jocks vs. Nerds )