There's a difference in laughing at people and laughing at
Friends: We laugh at Monica for being neurotic, we laugh at Ross for being even more neurotic, we laugh at Chandler for being a socially awkward smart-ass, we laugh at Joey for being a complete dummy, we laugh at Phoebe for having her head in the clouds, we laugh at Rachel for being a rich girl trying to live in a working-class world. But none of them are really playing any real stereotypes. They just have broad, humorous, personalities.
Seinfeld: We laugh at Kramer for being a "hipster doofus", we and we laugh at George for being a loser. And, really, they're the only two characters who we "laugh at." Elaine and Jerry probably got more laughs out of their stories than their personalities. We laugh at all of their failures.
Frasier: We laugh at Frasier and Miles for being overly elite metrosexual snobs and the failures they bring upon themselves.
But, BBT, seems to put on display four stereotypes of the "nerd." And we laugh at them for acting awkward and being so different than all of us "normal people." I mean, look at the scene when they walk into the diner wearing their cosplay gear. I mean, isn't it so funny we see these guys in costumes walking into a room full of normal people?! I mean they've been walking in the desert, they're dying of thirst, one guy had his car stolen. And, gee, one man-child had to call his mom for help!
That's very, very, different than, say, laughing at George for losing a job for not realizing it's bad to sleep with the cleaning lady on your desk. Or laughing at Joey for becoming the dance director of a musical because he lied on his resume.
The characters in those other sitcoms are broad archetypes of personalities. It's funny when things happen to them because usually they end up in the situation they're in due to their own doing.
Here? We're laughing at four guys who just got kicked in the balls because they're nerds. The one guy wants to take a picture of him and his girlfriend because NO ONE will believe he has such a hot girlfriend! Because nerds, you see, don't get hot girlfriends!
Ha! Ha! Funny!
We're not supposed to be laughing at these guys because of the situations they get themselves into or because they're causing their own failures. We're supposed to be laughing at them because they're "not us" and the world just kicked them in the balls, again.