Because we're smarter than that. We're smart enough to recognise when someone is clearly being racist and clearly intending offense. In the situations where it's unclear or when someone obviously is using the word in an acceptable context, and somebody gets offended and reports them, delete the post (and if you're so concerned about someone taking offense to a word being used in a non-offensive way, talk to them). Don't punish them. They've done nothing wrong. Just because somebody gets offended at something that isn't intended to offend doesn't mean you need to start throwing around warnings, infractions and bans. Focus on situations where somebody is truly being racist (or homophobic). Common-sense moderation rather than blanket ban moderation. Somebody's 'right to be offended' shouldn't trump somebody's right to free speech, especially when it's not even hate speech and intending no offense.