Nothing is wrong with PC. Just as nothing is wrong with tobacco, alcohol, fishing, hunting, drilling for oil, building shopping centers, planting crops, following our elected officials around with cameras, or playing loud music.
All of the above becomes counter productive, rude, dangerous, or sickening when taken to an extreme.
Political correctness is an extreme tactic that is constantly used by the Left to personally attack people who dare disagree with them and thus control the conversation.
And thus defend and advance policies they could not defend or advance honestly based on the merits of their policies.