Another concept that is dead, or ought to be, or is theoretically useless, is pc.
It ought to be dead from both perspectives: from the perspective of those who seem to be enforcing it, and for those who over-rate its importance for these very enforcers.
In the first place, it is a kind of linguification of real issues. If we can purify our language, then we can solve social issues. Of course, we should be careful how we speak, and what words we use, out of respect, but making that the main issue is never a good idea. Supposed people had a slur about people from Mars: the "Marties" and I accidentally said it when I was talking about mardi gras, or someone thought I did. So what?
Yet actually, people are usually not thinking about pc so much in the normal academic course of things, so the reaction to it is overblown as well.