Egon, aw, give Sheldon types a break.

It's obviously an exaggeration, but I know (and live with -see my post above) people like that and it's really not as constant or intense as all that.
If we are going to take the characters as they are, Leonard is the only bearable one, but as they are, I find Sheldon MUCH more acceptable than Howard and his crude come ons and Penny with her shallowness. And how could Raj possibly function at a university if he couldn't talk to women at all?
The good parts about Sheldon that are really portrayed well, if not often enough on the show are his loyalty, honesty and quirks like his ability to lend money without caring when he gets paid back. Also, his ability not to get his feelings hurt when people tell him to 'go away' or they decide that the best option to which movie to go to is to leave him at home. It is what it is with Sheldon.
On the flip side, someone like Penny who was freaking out about when she thought Sheldon was judging her for not paying him back - reading into everything he said and did with her own paranoid POV ugh! THat would be horrific to have to deal with. Or how about the time she had them spending time to help her make money she needed and then she went on line to buy shoes...
It's an exaggeration of her personality, but I would get along with a Sheldon type before a Penny type any day. On the flip side - what I like about Penny is that she is friends with the guys. She accepts their quirks and doesn't act like she's too good for them. If it gets to be too much for her, she leaves the apartment or tries to point out what's going on, but she doesn't write them off. Most people like her wouldn't be that accepting.
That's one of the things that makes the show so great - the exaggerations and the ability of them to still be friends despite it all. There are so many people in this world who write people off for a TINY quirk or difficult hang up. The best way to learn to navigate that stuff and still be in each others lives without judging is to figure out how to laugh about it.