I do agree with some of the points, but not all political correctness is just 'being nice', sometimes it DOES exist to surpress the speech of certain individuals. For example, I mentioned this a long time ago on these forums, but last year Ann Coulter was coming to my university. I was actually looking forward to it, not because I'm a fan of hers, but because I wanted to get in there and tear her a new one in the Q&A period. Anyway, a bunch of students got together and started protesting, declaring her discussions as 'hate speech' and 'politically incorrect' (which my god can be applied too broadly).
They protested outside of the building, and began to do some very questionable things after awhile. Flipping over tables, pulling fire alarms, threatening people collecting tickets and generally just blocking the door. Now, this is a university, and I expect that I should have the ability to challenge beliefs in Coulter's in a forum. But no, these students wanted to completely eliminate her event, despite not knowing what she would even talk about. 'Being nice' is not threatening ticket collectors because they are working for an event you dislike. Eventually the event was cancelled.
What's the true, mature response to people like Coulter? To challenge them in a debate and delegitimize their position. Now Coulter looks like the victim and gained sympathy, further helping her along. I'd rather have my racists/sexists/etc. screaming their opinions loud and proud, so we can look at them and realize they're idiots. Political correctness does nothing to solve the underlying problem, it just covers it up. These people still have 'politically incorrect' views, they're just not vocal about it. And it terrifies me that they could end up in positions of political power without people knowing.
But maybe I'm just some horrible, sexist, racist, xenophobic jerk like Bob notes.