Put simply, the one thing that people tend to forget when they bitch about political correctness or any other scapegoat that they claim is restricting their freedom of speech - that just because you can let anything that you can think of come out of your mouth doesn't mean you're off the hook for doing so.
Usually, when you hear one of the usual suspects complain that their freedom of speech is being infringed, the claim usually takes the form of "Well, I can't say what I want to say because if I do, I'll get villified." Well, guess what - just because you're afraid of what will happen if you say something does not mean that your freedom of speech is violated! In the US, at least, all freedom of speech means is that as long as your speech does not fall within a small range of proscribed forms of speech (i.e. libel, slander, obscenity, yelling "Fire!" in a crowded theater, etc.), the government has no right to proscribe or criminalize it. That's it. There's nothing in it restricting how any private individual or organization may react to what you say, for better or worse.
So, the government can care less if you want to let loose on a bigoted tirade. That doesn't mean that your community can't turn you into a pariah because they don't condone your words. It doesn't mean that your employer can't fire your ass because they don't want to be associated with you (unless your employer IS the government, and even then that's not always a guarantee.) In short, the government fully protects your right to shove your foot firmly into your mouth - for good or bad. But it's not there to protect you when you manage to piss everyone off with an ill-timed, intemperate remark.
And let's be honest - that's the way it should be.