Extinction Rage
Suppose you train a monkey to push a button, by rewarding it with a banana every time.
Then you stop giving it bananas.
What happens next is called Extinction Rage (technically, "Frustrative Nonreward.") The monkey becomes angry and agitated.
You may have experienced something similar, when a vending machine took your money and gave you nothing in return.
Extinction rage may be accompanies by an "Extinction burst." Paradoxically, when the bananas stop arriving, the monkey pushes the button more, at least for a while.
(In this context, the term "extinction" refers to the death of the monkey's belief that a button press will be rewarded with a banana. It's a sad time for the monkey.)
In the 60's, right-wingers trained leftists to call us racists. When they called us racists, we dropped loot.
Pushing the racist button was always rewarded with loot, and better yet, with the right-winger's cowering submission.
So leftists pushed the racist button a lot.
Then a few years ago, most right-wingers stopped dropping loot. In classic extinction behavior, leftists got angry and called us racists even more. They frantically pushed the racist button, hoping the bananas would resume, getting angrier and angrier when they didn't.
Some leftists are still pushing the button.
I'm sure you can make the connection to the sexist button, as well as the homophobe, islamaphobe, and trans-phobe buttons.