Well that is a primary difference in usage of terminology.
Diversity within a single culture is a wonderful thing.
Diversity of several cultures to the exclusion of a single culture is what most liberals are pushing for.
So, yes, diversity is a good thing, but maintaining a single culture is paramount.
Good points. There is something I'd like to have clarified however. I know a racist or two, they insist that their bigotry has nothing at all to do with the skin color. They say that would be like saying they don't like Castor Oil because of the color of the bottle. They claim that it is the "culture" that they find derogatory.