So does Star Trek for some trekkies. So do soap opera characters for some fans of those. I'd be most interested in you pointing out a fandom [or any part of the human society really] where you don't have those overobsessed with some or another aspect of it. So being obsessed with football, soccer, cars, politics or somesuch is fine because 'normal' people do it, but other interests are not? My dad commits at least as much time to following and discussing sports as I do furry.
And to paraphrase 2, whatever you may think of the fandom, at least we're not out there shooting people and raping babies .