Why do White people in an attempt to defend Racism, pretend it doesnt exist?

I acknowledge that racism exists but I don't think most people understand what it means. It means that one group of people believe that another group is inferior to them in some way. Man is a tribal animal and will always gravitate towards those that he sees as being 'the same as him'. This goes for black people too. It doesn't make them racist necessarily. Why do you suppose we have enclaves of people living in Britain who come from Asia. Because they want to live with people they identify with, Why is that not considered racist when it is considered racist for white people to want to live in an all white area? I am certainly not a bad person, nor am I a coward. I dislike multi-culturalism but that doesn't mean that I consider other groups inferior. I just don't believe it works and it never will.