Dismissing someone's request for civility by calling it "PC" is extraordinarily rude. You can easily change your own behavior, and request the change of others, if you choose to accept it as an important change.
Failure to do so indicates disinterest in listening to the people who feel this is important, or take their concerns seriously. That is a personal judgement about the validity of their interests; you're just papering it over with free-speech language to pretend otherwise.
Do you insult your parents or loved ones to their face and then claim that it's "PC" to demand you not do so, or argue that only "official" insults should be heard and all others ignored? No. Because you care about respecting them. That's it. That's the whole issue.