"The reason people don't understand why PC becomes so entrenched is because 'political correctness' is itself a phrase that obscures the institutional rationale for things. PC is nothing more or less than advanced, institutionalized liberalism. I have come to dislike the phrase 'political correctness run amok' very strongly. It suggests that just a little bit of PC would be sensible, or that PC is just an extreme version of something basically rational, which it's not. You can't identify and combat 'political correctness run amok,' because it's a meaningless way to describe the phenomenon.
"The phenomenon is liberalism, and the reason Western society is in the death grip of political correctness is because PC is an expression of the death grip that liberalism has on all our institutions--the media, the military, the universities, the mainline churches, etc. All of them are PC because all of them have, in ways unique to the character or charism of each, adopted the essentials of liberalism. In particular, the belief that erasing distinctions--and particularly categories as they apply to human beings--is the highest possible calling in life, somehow residing at the core of the institution's mission, is the liberal ideal to which all Western institutions now subscribe.
"What Larry Auster sometimes calls the non-discrimination principle, that is, the notion that discrimination is the single greatest possible evil and that all goods are tertiary to the good of advancing the liberal ideal of non-discrimination, really is the ruling principle of our society. Recognizing this fact makes every single instance of PC madness fully comprehensible. It also explains why everyone knows by instinct the seemingly byzantine demands of PC, even when they aren't written down anywhere. Being based on such a simple principle, people are able, instantly and without reflection, to apply it to any given situation at all. Finally, recognizing this fact also explains why people are so hopelessly confused by it all--they accept the basic premises of liberalism, and they largely know precisely when and how to cringe before its demands ('Not that there's anything wrong with that!'), but they nonetheless are baffled when they see institutions behaving in accordance with the raw, anti-rational radicalism of the non-discrimination principle. They fail to identify liberalism as such as the source of the problem, being basically liberals themselves, so they blame it on some hazy thing called 'political correctness.' Moreover, they realize that this is an expression of something that they basically accept, and cannot repudiate utterly, so they say that it is somehow 'run amok.'
"If people would simply call it what it is, that is institutionalized liberalism, we could at least have a debate on the real causes of such insanity and decide whether we really do think the sacrifice worth it."
...to almost all of which I say: bravo! bravissimo!. The phrase "political correctness" has probably long outworn its usefulness.
The only criticism I'd venture here is that I think it's far too generous to the left to take at face value their supposed dedication to anything legitimately describable as a principle of "non-discrimination." In fact, the left systematically, relentlessly, and shamelessly discriminates - against whites, against males, against Christians, against Southerners, against the working class, etc.
I think we need some other way to sum up their worldview.