Why do some people detest "political correctness"?

Saying what you think is important, but not showing enough respect for people with whom you disagree is a disgraceful behavior. Bullying your rivals and speaking bullshit have nothing to do with the concept of freedom of speech. If you really think that what you call "political correctness" is a bad thing, why don't you instead call it "political incorrectness" and reject it completely all the time? If you do not say what you want to say, you do not need the right of free speech.