Religious opinions are divisive, we took our side, and don't seem to be considered very highly by those who took the other.
I don't mind closing the community to believers, in first approximation their ideas are worthless. But I wouldn't extend that to liberals, libertarians, conservatives, environmentalists, anarchists, etc.
I can't think of any other topic beyond religion and politics where it's commonly expected that everyone has a position - some people can have strong and conflicting opinions on say parenting styles or whether Esperanto is a real language or interpretations of quantum mechanics or operating systems or whether Batman could beat Superman, but they don't go around saying "Oh yeah he disagrees with me because he's a yellowist" or something like that.
Are there any areas of study that you feel are underrepresented here, and would be interesting and useful to lesswrongers?
I feel some topics are getting old (Omega, drama about moderation policy, a newcomer telling us our lack of admiration for his ideas is proof of groupthink, Friendly AI, Cryonics, Epistemic vs. Instrumental Rationality, lamenting how we're a bunch of self-centered nerds, etc. ...), and with a bit of luck, we might have some lurkers that are knowledgeable about interesting areas, and didn't think they could contribute.
Please stick to one topic per comment, so that highly-upvoted topics stand out more clearly.