PC started as a semi-ironic thing on the left, at places like UC Santa Cruz, a mockery of Stalinism but applied to trivial things. "Smoking is not p.c."
Then came the culture wars of the 90s. The term "political correctness" became applied by the right to the left. The idea was not that racism is bad, but that the over-sensitivity to perceived racism, sexism, or whatever is the real problem. It is easy to see that this is a ruse. Instead of arguing about real issues, we begin to debate the nuances of tone, and measure outrage. The right's own culture of grievance mirrored the culture of grievance supposedly on the left.
(Academic administrators did enact hideous speech codes, in an effort to be more pc.)
Now it is true that outrage can be phony, or exaggerated, on either side. I can be outraged that you are outraged, or not outraged, or that you are more or less outraged than me, and so on. That you care more about one trivial thing (in my eyes) than some more profound thing that is much worse (for me). This is all more or less absurd posturing, of course, fostered now by the quickness of social media. It is a false politics of staged grievances.
There are real issues to be debated, though. The culture of staged outrage serves to cover up those issues, not to reveal them. Now who is to decide what a real issue is?
Naturally, it is me, because I am smarter than you. But seriously, anyone can do this. Just analyze the situation and decide what the real issue is behind the faux spectacle of outrage.