As I understood the basic idea of PC, it was introduced to eliminate subliminal prejustices in common, daily used language. This language originates in a past where people had different values than today. So PC was basically an attempt to lower tensions in society and therefore is an exellent thing to do.
Unfortunately the opposite of "well" is "well-intensioned" - there is no doubt that this attempt didn´t achieve all of the desired objectives. Partly it replaced old dogmas with new ones and introduces a number of new necessities that complicate communication instead of relieving it.
The biggest sucess of PC is, however, a debate about the power of words and it´s massive impact on society. Orwell´s 1984 is an exellent example how people can be manipulated.
The solution for the problem of manipulating language is, in no case, simply to manipulate the other way ´round. PC is often degenerated to a term of daily political conflict.
I cannot agree though with some statements above, PC had a massive negative impact on our lives. That´s a bit too hysterical for my taste (we don´t wont to be the said whinos howling about the naive do-gooders, don´t we?).
At last, we all use our own words. If someone is offended by PC, he´s actually offended by the fact that other people could misinterpret his words. In my view, the only concern someone should have talking is to be understood. If someone else want´s to misinterpret deliberately, he will do so if you talk in a political correct way or not. So what is all the fuss about?