Why does American Internet Sites enforce Anglo-American Political Correctness?

Why do American internet sites enforce Anglo-American PC? I though America was supposed to be a land of multi-culturism of people from all ethinicities, cultures, lanauges, and religions. Yet Anglo values are constatly shoved down our throats. To the Anglos out there, did you know that the conversations that Armenian-Americans, Chinese-Americans, Mexican-Americans, etc are different then what we talk about infront of mainstream Americans. The reason why is that we constanstly have to worry about people being racist against us because we speak about views and topics that we have because of our cultural background and doesnt match up with Anglo-American culture. This is getting out of hand. An American citizen should be able to function in America without having to worry about hiding their cultural background or having to worry about large corporations, media and government going after them because of thier culture. Why is it so mainstream that people can do this in a country that