As usual, I'll add that I think that one major cause of these problems is the totalitarian inclination of the left. It's radical and generally tends to radicalize more over time. Conservatives tend to resist change, the left tends to welcome it--in a certain rather narrow range of directions--always leftward. It also tends to see its political ends as constituting the most important ends, ends that override all others. In academia, even the search for and transmission of truth, and the transmission of the best that has been thought and said must be subordinated to leftist ideology. Free inquiry, objective research, free speech, all are merely subordinate, so all may be subordinated. It's not merely that political considerations sometimes override other goals--they always do. If free and open inquiry requires questioning the new leftist axiom that some women are male, then so much the worse for inquiry. Hence political correctness--the subordination of actual correctness--truth, justification, evidence--to that which is deemed correct by leftist idealogues.
Some have even suggested that the left is driven to radicalization because leftists gain internet cred by adopting more radical ideas than their peers--the crazier/leftier the ideas, the greater the cred. Credo quia absurdum est.
If leftist ideas were crazy, but the left weren't hellbent on injecting them into everything and re-engineering society in accordance with them, that would be a problem, but a lesser one. Or if the left were dedicated to injecting certain sane ideas into everything, that, again, would be a problem, but a lesser one. But the combination of radical, obviously absurd ideas with the totalitarian objective of injecting them into everything...this is a catastrophic combination.
This is all made possible by another characteristic of the left, the acceptance of bad philosophy and bad methods. The former include relativism and social constructionism, the rejection of the very possibility of even moderate degrees of objectivity, skepticism, nihilism, subjectivism, prope-Marxism...the list goes on and on... Add to these the academic left's introduction of bullshit, quasi-poetic, free-associative methods of reasoning that allow basically any conclusion to be "derived" from virtually any premises via inscrutable, irrational, jargon-laden bullshitting. Check out the writings of its heroes--e.g. that champion of transanity, Judith Butler. Utter bullshit. Not to even mention people like Bruno Latour, Deleuze, Helen Longino--hell, you can just throw in almost all the famous feminists of the last 50 years--Lacan, much of Foucault, most of the critical theorists... What you find in such writings is mostly bullshit--bullshit promoting left-wing ideas--pasted together and obscured by neologisms and inscrutable, quasi-poetic prose. Undergraduate-level reasoning behind a smokescreen of pseudo-scholarly cant.
This method meshes will with another of their favorites: ceaseless, groundless accusations of prejudice--racism, misogyny, a whole array of "-phobia"s--against anyone they disagree with. The left is always able to "find" "racism" in anything its opponents say or do because (a) it is a philosophical assumption that all their opponents are racist (etc.), and (b) their "method" of "reasoning" is so loose and free-wheeling that they can, with enough babbling, "prove"--i.e. assert--anything they want.
And, of course, we should add: they even deny the difference between genuine inquiry and sophistry to promote political ends. That's a liberal, rationalist hangup, my friends. One reason they adopt the view that "everything is political" is so that they can, with a clear conscience, slander their political opponents even when they know they are lying. Truth is your hangup, liberal. Nothing trumps the importance of the revolution...
And here we are...a hundred million broken eggs, and not a single omelette...
Anyway.
My $0.02 FWIW...