Political correctness gets a lot of shit. There's the idea that it's purely censorship, that it's oppressive to language, that everyone is just too fussy and oversensitive. We've defined it with a negative stigma so that we can condescend to anyone's protest about offensive material by labeling it as just another attack from the PC thought police.
Comedian Stewart Lee does a great bit about political correctness that dares go against popular opinion: "It's an often clumsy negotiation towards a formally inclusive language," says Lee. "There's all sorts of problems with it, but it's better than what we had before."
That's about as level headed as the discourse on the nuances of political correctness gets. The problem with most of the discourse on PC is that it is seen in the context of a battle, with wins and losses and very tangible goals. A watchdog group speaks out in protest against an insensitive remark in the media, and then that target attacks back, and they try and take away other's legitimacy/career.
The problem with that rhetoric is that it forgets that this is a cultural conversation, not a gladiator arena. There is not going to be a winner and a loser, nor should we be aiming for such. While there may be short term accomplishments (Dr. Laura loses sponsors for racist remarks on the radio) what they're really talking about (the use of the N-word) isn't resolved. The point of having watchdog groups raise their voice, and even the point of people attacking those watchdog groups, is for the rest of the world to gain access to this conversation and make adjustments to their lives if they see fit. This is how culture evolves.