Most people wouldn't get upset specifically at you for defending them. It's sorta a cringe reflex for most people, especially whites I've seem to notice. The situation is this: we all agree racism is wrong. What we are arguing about now is whether or not skin color should be kept sacred, or are we all equally worthless? Those that believe skin color is something to be kept sacred tend to be politically correct and will avoid word usages like nigger, the opposite will instead go as far as saying race jokes because they value skin color so little. People from both sides seem to see only the negative in the other. Politically correct individuals believe the opposite is insensitive and part of the problem, the opposite side believes the others have a white knight issue whom is fighting a battle that doesn't need to be fought.

Basically, short answer, is not everyone thinks it's necessary. It's just something you wont see as often in public because most of us don't want to fight the battles associated with the witch hunts that are common place.