Discussions of political correctness are meta-discursive. In other words, they concern speech acts and responses to them, mostly. These responses, and the responses to the responses, are also meta-discursive. It's language about language about [whatever category is being contested.]
He said the word _____. People reacted by calling him on it. They said he was _____ -ist. The counter-reaction comes when he claims to be a victim of political correctness. His speech was curtailed because he was called a _____ -ist for saying the word _____.
But those who call him a blank-ist have their right to speak just as much as he does. In groups where everyone wants to be perceived as virtuous, being called ____-ist is the worst thing possible. Things can spiral downhill fast. The left's concern with comfortable spaces cannot be maintained, because the right can mimic the discourse of victimhood, insult, and comfort level. Even within a group of like-minded people, the right to speak becomes contested. Easy for me as a white male to say, right? But that's the whole problem.
Once the question gets to be: who has the right to speech, and how much, and in what tone, then the debate becomes absurd posturing.
It's not "politically incorrect" to perform actual acts of racism, like not hiring someone because of her race, or incarcerating a large portion of members of a certain racial group, but only to intervene in a debate by saying the wrong thing. It is a very limited power of critique, because the racist has to out himself by saying something foolish in the first place. Social media makes the problem worse, because you get more opportunities for gaffes, and a shorter news cycle.
It was a huge mistake to make all these political debates about the symbolic politics of speech acts.
That being said, suppose you had a purple elbow. Your whole life, people are commenting on it. "You throw a football pretty well for a guy with a purple elbow." "How'd you get that purple elbow, anyway?" "Hey, purple-elbow, go back to Purpleelbowstan." "How does it feel to have a purple elbow?" "Can I touch it?" "Some of my best friends have purple elbows."
Some people are cruel, some thoughtless, some indifferent, some naive, some well-meaning. Some have dedicated themselves to not be prejudiced against you. But each person's interaction with you is just one interaction, for that person. For you, though, that one interaction is part of a never-ending pattern. Even the relatively innocent comments are part of a pattern of harassments. To dismiss them as micro-agressions of no importance shows an astonishing lack of empathy.