In the absence of a metaphysics which places morality at its core - it's been necessary for our culture to have a traditional conception of political correctness to keep discrimination in check. Without some kind of contraints on our language to act as a continual reminder to treat others with dignity and respect - our culture would not have made the advancements it has in terms of improving the rights and wellbeing of minorities.
One. It has started to be taken too far. Originally intended to protect the minority - certain minorities have begun to make unreasonable demands seeing themselves as victims requiring continual and overly dependent support.
Two. Having spent the majority of the last 50 or so years on improving social injustice issues, american politics has neglected the importance of social equality and the rich/poor divide. Therefore this gap has grown so far that the disadvantaged and poor are fed up with the focus on Political Correctness and rightly see an exclusive focus on this as part of the problem. Recognising this trajectory - this was predicted by Rorty in his book Leftist Thought in the 21st Century, 1998:
"One thing that is very likely to happen is that the gains made in the past forty years by black and brown Americans, and by homosexuals, will be wiped out. Jocular contempt for women will come back into fashion. The words ‘nigger’ and ‘kike’ will once again be heard in the workplace. All the sadism which the academic Left has tried to make unacceptable to its students will come flooding back. All the resentment which badly educated Americans feel about having their manners dictated to them by college graduates will find an outlet."
Richard Rorty - Leftist Thought in the 21st Century, 1998.
Three. With our current metaphysics we're unable to easily determine the line between protecting what's good about a minority and validily criticising it from the standpoint of our culture so that it can assimilate into our culture. Whilst the Metaphysics of Quality doesn't resolve these disputes once and for all - it provides us with a beautiful logical language to discuss these issues.
For example, the MOQ provides us with a clear distinction between biological people and the cultural values with which they identify. One of those things does not matter and cannot change, but the other does matter and can change. Criticism of that which can change for something better is considered moral in the MOQ. Whilst criticism of a person simply, for example, because of the color of their skin is logically racist, evil and immoral.
So the general solution isn't to throw away the value of Political Correctness. As mentioned - it's moral and supported by the MOQ. Instead we should aim to solve these problems in a different way. Solving cause One would likely be with certain education reforms and certainly reform the way we have traditionally taught discrimination resolution.
Solving cause Two isn't to throw away political correctness but to simultaneously tackle social income inequality at the same time. In fact oftentimes, it's minorities who are economically disadvantaged as well - thus tackling both of these problems will likely take pressure off them as scapegoats for a suffering majority. This will also also improve their social mobility with a smaller wage gap between them and their neighbours.
Finally, solving cause Three would involve further cultural dialogue using the moral language of the MOQ to guide us in a better, moral direction.