I saw a reference recently that summed up why I dislike The Big Gang Theory: "Nerd Black Face." It is treating the nerds and geeks on the show as unself-aware fools for "real" society to laugh at.
No other social group or category would stand for this - it's basically blatant racism, but because it's not applied to a specific racial group but instead a social category, it's "funny" rather than "bigoted" or "mocking".
Can you imagine the outcry if there were such a show about blacks or Chinese people? The NAACP or Chinese community groups would sue the network so fast that their heads would spin!