Because feeling better about one’s self by punishing others is an addictive pleasure, victories can never satiate those who wage identity politics as war.My perspective of those infected with political correctness has been that they are callow virtue signalers and moral preeners. They do what they do for their own self-serving ends, not out of respect for others. In many cases this extreme narcissism takes the form of fanaticism. Arguing with those tainted by the fanaticism of political correctness is a fool's errand. They have no logical, rational or evidentiary grounds for their linguistic position. It is pure linguistic theatrics, and puerile theatrics at that. Until their own cognitive system rids itself of the infection of political correctness, there is nothing you can do for them. All you can do is save yourself the time of arguing with them.
Codevilla offers a variant explanation which I suspect has merit. He doesn't address virtue signaling but posits that there is a darker motive at work - vindictiveness. It is a well established psychological condition that, as inherently social animals, we are genetically disposed not only to reward good behavior, but to actively punish bad behavior. In economics, experiments have yielded quantifications indicating that people are willing to expend resources in order to punish rule-breakers, even when there is no yield in benefit back to the punisher. That is just our genetic inheritance. We are collaborative and everyone else should be as well, at risk of punishment.
So people get a rush by punishing others whom they think "deserve it." And those infected by political correctness have elaborate ideological justifications for punishing others who are less linguistically or emotionally refined than themselves. They have lots of latitude to generate the emotional thrill to themselves by punishing those whom they deem lesser spirits. A latitude which they fully exploit. An addictive pleasure indeed.