Political correctness is - at its deepest level - based upon a human experience.
This experience is one of having in the mind an abstract and ideal sense of how things ought to be, and a perception of how very far away from this are actually existing states of affairs.
Thomas Sowell has talked of Cosmic Justice - which is the ideal of matching actually existing states of affairs with this imagined abstract and ideal sense of how things ought to be.
Against this deep inner experience, 'pragmatic' ideologies such as libertarianism have little traction.
Anything which advises people to be 'realistic', accept humans 'as they are', or to work within 'constraints' is perceived (by the devoutly PC) to be an evil temptation.
Because the difference between the ideal abstraction and perceived reality is qualitative (not quantitative).
This is why PC has no 'sense of proportion' - this is why (under a dominant PC public discourse) a single casual overheard private comment can lead to an international crisis of perceived racism, sexism or whatever - because there is an infinite difference between the ideal abstraction and anything which falls short of it.
Any imperfection relative to ideal abstraction is therefore the tip of a vast iceberg of wickedness and corruption.
And of course this is perfectly true.
Libertarians and pragmatists who attempt to deny the pervasive sinfulness of the world, or to argue that the possibilities of good are severely constrained, or that selfishness can be made a means to attain the good (as in market economies, or in natural selection) are therefore perceived as apologists for evil.
Which indeed they are!
Therefore, devoutly PC have as their starting point the same experience as all deeply spiritual people - the problem of sin: of humankind's innate corruption.
But since PC is wholly this-worldly and materialist, they have a priori ruled-out any possibility of a religious answer to sin.
Therefore, political correctness is engaged in a search for this-worldly 'salvation' from a sin which is perceived to be intrinsic to all humans!
The pre-PC answer was communism: which saw humans as products of the environment.
For communism, if the environment was right, then humans would be free from sin.
And when humans were made free from sin, then the system would become self-perpetuating and the state would 'wither'.
Totalitarianism was only temporary; a means to the end of an ideal anarchy of sinless humans.
Political correctness comes after communism, and is a response to the recognition that the 'ideal' society does not eliminate sin.
With PC there is no expectation or desire that the state will 'wither' - rather the implication is that the state should be all pervasive.
The implication of PC is that totalitarianism is not just a transitional state, but the desirable form of human society.
In other words, since humans are (it turns out) incorrigibly sinful, then they require permanent and all pervasive supervision and regulation by 'the state'.
And in PC 'the state' must become abstract - must not be a matter of specific human beings, but an abstract system which is (ideally) independent of the humans beings who happen to be implementing it.
So the ideal of political correctness is an eternal, all-monitoring, all-controlling, all powerful, impersonal abstract state.
Once this is in place everywhere, it will become self-sustaining.
And humans will not longer be able to be sinful.
Humans will be made to be virtuous - not by other humans (who are sinful) but by a perfected abstract system.