Hmmm. This is a rather hot-button issue, isn't it? Personally, I subscribe to the "Yahtzee theory": a society in which anyone can call anyone else anything they want and just laugh it off is a truly accepting society. However, when we ostracise every singly bloody comment a person makes, we simply continue to create racial division, as people stop trusting in one another.
Take this example: let's say you're white, and you're hanging out with a Hispanic friend. The two of you are making jokes about one another's homelands, and your friend calls you "A haggis-sucking, dress-wearing bastard," to which you respond with something about equal on the "racial insensitivity chart." You both laugh your asses off, but a nearby man, who heard both your comments, gets up and chews you -only you!- out for what you said, inadvertantly using some slurs himself. When he stops, your friend agrees that the guy was being a dick, but now he's got a little niggling worm of doubt that says that maybe what YOU said was racist. So now, not only have you been condemned for something simply meant as a glib, meaningless insult, but now society itself is looking down on you for it. Furthermore, these notions of racism, sexism, and other things are hard to brush off: once you've been marked, I'm sorry to say, you're kinda fucked.
Not only that, but people label you as these things for such stupid reasons. I had a friend who called me racist because I didn't like a TV show. His reasoning: THERE WAS ONE MORE BLACK CHARACTER THAN THERE WERE WHITE CHARACTERS. Yeah, fuck'im. I just didn't enjoy the fucking show! And you know how he responded? He yelled out, in the middle of our middle school, which is filled with Hispanic kids, "Liam hates beaners!" Right then, I wanted to strangle the prick; yelling that out about the person on our campus was signing a death-warrant. I never did get beat up, but I still got pissed at him.
It seems to me that this system of judging racial injustice and insensitivity seems to leave white guys, like me, with the extremely short, pointed, "well-at-least-you-can-jab-yourself-with-it" end of the stick in daily conversation. We can't openly respond to the slurs of others without a cultural backlash, even if it's just to respond to a friend's comment. Now, there's obviously good reason for this- we've smashed just about every other culture in the world in the face- But even then, why should we descendants pay for the sins of our ancestors, when no-one except for white people have to? Why not give Egypt grief for enslaving the Jews? Why not hassle the Mongolians for their brutal conquests of hundreds of nations? Why not ostracise the descendants of the Aztecs for their horrific enslavement of other local civilizations? Want to know why? It seems that it's because they just haven't done it on the same scale as us Europeans. However, even the act of refusing to treat these injustices simply because of some racial background should be judged as racist in of itself.
Obviously, there are limits to this: there are areas that should be "verboten" even now, such as the Holocaust. But even then, the fact that we give these terrible things so much meaning simply shows how juvenile our society is, not the other way around, like a kid laughing at the word 'dick.' When one can't say something without ostensibly offending racial sentiment, it simply shows that our society has not, as a whole, progressed to the point of social maturity at which we can recognize these words for the meaningless, glib insults they are, and laugh them off like normal adults.