I really can't think of a large site in which discrimination for muslims/democrats/gays/blacks isn't more frowned upon than whites/republicans/christians etc. Even places like 4chan are mixed bags. Even MSM if you want to count that.
It has to be frowned upon because it is so prevalent among fringe hate groups. If you don’t have strong moderation and social norms around it, hate against those groups is what drowns out the other text. 4chan is a great example, if you remove moderation hate against those groups seemingly spontaneously arises.
