I have written about Political Correctness (including its origins) many times on the website, but the moral seems to be this: conservative objections to PC miss the point and may even antagonize minorities and women by appearing to lobby for incivility.
It is not the entire Left that has imposed speech codes, but a particular branch of it: the postmodernists who believe, like other trendy mystics, that language (as mediated by institutions) creates reality. So social democrats and Leninists alike may emphasize changing speech all by itself. But their protocols do not improve institutional controls that would indeed further the goal of intellectual diversity (also known as the marketplace of ideas; see https://clarespark.com/2015/12/29/milton-friedmans-capitalism-and-freedom-1962/).
(Real) leftists reject all capitalist institutions as bogus leftovers from earlier set-ups, while social democrats are out to stop the far Left through co-opting and erasing class as an analytic consideration; also the same phony liberals erase fact-based history and perception as “vulgar.”
(To the extent that Marxist-Leninists believe in the “telos “of history, they participate in the same mystical folly. The materialism of the Enlightenment is rejected by Leninists favoring dialectical materialism.)
When I brought this subject up on Facebook, I saw that one or two friends, believed that minorities and women were deficient in those qualities that make (what passes for) success in the modern world. That too is a rejection of history—for instance the astounding vanguard that created the US Constitution minus all the Founders’ class positions (i.e., their historical situation)—which accounts for their support of slavery and of the secondary role of women.
How odd that some “conservatives” idealize those aspects of the Constitution that suit them, while undermining politeness—a very democratic, if bourgeois, concept.