Because people have become soft now days. They think that it's derogatory to call someone black, when actually that is what they are. I prefer to call them by their name if I know them, but so many people get offended just by stupid things like calling people black, mexican, white, or whatever else.
I don't really care about racial slurs. I mean, I'm not going to go out of my way to call some black person a negro or whatever, but I'm not going to throw a fit about it if someone does or if someone calls me a derogatory name like cracker or gringo or what have you. That's life, some people are going to call you or someone else names like that, and you can either choose to throw a fit about it, or just understand where they are coming from and move on.
I am not racist, nor do I discriminate against anyone. Life's too short to spend it being or doing either of those things.
Avy & Sig credits go to Hurricane0