I suppose it depends upon how one would define "political correctness". I think of it as exhibiting excessive conformity to some arbitrary standard out of self interest. Some who like to use vulgar, obscene, and prejorative language see it as an assault on their prerogarive to speak as they please.

It doesn't help anybody to demand, for instance, that we all refer to mentally handicapped people as "differently enabled" or even "special". These are euphamisms, used only for the self-serving purpose of avoiding the appearance of insensitivity.

Euphamisms soon become epithets just like the words they replace. The word "retarded" is, in fact, such a word, originating in the public schools to describe progression through the system at a reduced, or "retarded" rate. It was a kinder substitute for the term "idiot", but has become a synonym for that prejorative word, and hasn't helped the situation in the least. On the other hand, casually calling mentally handicapped people "retards" displays a failure to recognize those persons as having value. It is all too easy to fall into the awful habit of promoting oneself by denigrating others. This is a matter of empathy, not political correctness, and no amount of imposed correct-speech will alleviate the problem.

I personally believe the character traits that govern an individual's empathy for others, or the lack of it, are almost completely established by the age of five years or so. In other words, before the kid leaves home for school -- it comes from his parents. The careful reader will, of course, recognize my use of the term "mentally handicapped" as another euphamism, which I employ here to avoid the appearance of insensitivity.

The same ideas apply to all kinds of "differences" among people (and other species, as well). People naturally tend to band together with similar people, and exaggerate the differences that distinguish "us" from "them". For instance, perl and Java programmers are wont to deride one another, which is nearly always counterproductive and ought to stop. This natural behavior is, in most instances, no longer beneficial to our species, but requires effort and training to overcome. (Lisp coders, on the other hand, are hilarious. You see the difference?)

Discontinuing all prejorative terms, however, would deprive the language of such gems as: "Arguing on the Internet is like competing in the Special Olympics: Even if you win, you're still retarded."

How, exactly, should one strike the balance?