That kind of stuff is just the pillar of vapid slacktivism, chastising people for language they use rather than the ideas they spread.
Some time ago, it was "ok" to call a person cripple. Then that was no longer "polite" and people were called "disabled". When that wasn't seen as polite, it changed to "handicapped", which itself turned into "handicapable".
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What I am trying to say: Language always evolves but it seems supporters of PC don't understand that using a different term doesn't make the prejudice attached to the old term suddenly vanish. It'll just slowly affect the 'new' term until it is considered impolite and a new, even more ridiculous, term is coined.[/edit]
Somewhere down the line, the idea of being super PC just lost me and I try to be generally polite and open instead. So when I use a term people are uncomfortable with, I apologize and adapt my language (well, at least within certain boundaries).
The way I see it, PC is a tool for imbeciles that can't grasp the notion of "not being a dick" and using general politeness. It's not like you need the concept of PC to not walk around and call people slurs like "n*gger" or "cripple".
On top of that, the choice of words isn't as important as the mindset and behaviour the person displays.
That is to say: I guess being discriminated isn't so bad when the other person at least uses PC-language while doing so.
That's actually one thing I wonder about. These attempts to be super PC always look to me like they drive a stake between different categories of people. Like, the whole concept of PC tries to pidgeonhole every person it encounters, so rather than expressing respect, it looks like a really elaborate system to categorize and rate people.