Penny is so obviously the fish out of water character that the audience is supposed to relate to. People laugh when the "nerds" do something that is socially awkward from Penny's prospective. The writers obviously intend it to be that way. I don't care about the laugh track at all. "That 70's Show" had a laugh track and it was funny. It is filmed live so it is hard to get around it. I am a physicist and a huge scifi/fantasy geek but I do not relate to the show at all. My parents do. My grandma does. My uncle does. People I randomly meet who find out my profession love the show. I rarely meet other physicists and/or geeks who like it. I think the humor is simple and childish. Also, the show is sexist. Even the female scientists aren't geeks. In that universe females do not play D&D, read comics, play video games, read science fiction and fantasy. The females encounter these subjects through the males and usually mock them for it. Even Raj's girlfriend (played by Kate Miccuci) isn't a fan of comics even though Raj met her at a comic book store. The writers made it so she just went to a comic book store as part of her therapy for her social anxiety. It relies on tired and worn out tropes that have been around since Revenge of the Nerds.