[shib71]

I personally find the characters very sympathetic and laughing at the BBT characters is like laughing at myself. It's refreshing to see the extreme qualities which other shows merely caricature be shown in the context of fully fleshed out human beings.

[dkuntz2]

BBT doesn't flesh out those characters. Most other shows I watch do.

Ben Wyatt on Parks and Rec comes off as a much more realistic nerd than any of the characters on BBT.

Abed Nadir in Community is also a whole lot more fleshed out than the characters in BBT.

The BBT characters are the epitome of stereotypical, caricatures of nerds. None of them are ever shown to have interests other than the traditionally nerdy kind.

If by "fully fleshed out human beings", you mean they happen to be main characters, sure. But by any other definition of "fully fleshed out" vs "caricature", they're much closer to caricature.