I don't think we really have any right to criticize people's mannerisms. Sure, there are people that bug us because of the way they act, and I have been annoyed by many a flamer over the years, but still, this is just how a person acts. I'll bitch about how a person acts, or how I wish they wouldn't act so, but we really have no right to place a person under a social norm. To say a black person is wrong because they don't act "proper" enough, or to criticize a gay man because he acts too flamboyant goes against everything we preach of freedom of expression. We might not understand a persons mannerisms, but we all come from our own corner of society, and in this sprawling American zoo, we all have different norms. A person acts they way they do because that's the environment in which they were raised, not because they're trying to make a social statement. Sure, there are those ass holes who are trying to turn themselves into a tidy little stereotype, but I think they're a lot less common than we realize.
If we really expect to achieve equality, then we have to be willing to shed our own prejudices and see it all in a new light. Otherwise, we'll all be chasing our own tails and pointing fingers, finding blame in one group to the next.