I have come to realize that one of the problems of those on the left is the echo chamber in which they live. This board may be their only interface with the real world.
I haven't had time to read every post, but did somebody earlier say that those not aligned with the 'Right" aren't necessarily "Left"?

That is the most succinct summation of the problem I think. Most liberals don't believe they are liberal. They believe they are perfectly rational, normal, and have it all together while all the rest of us are out of sync with the real world.
As a journalism major and being part of the media off an on throughout my adult life, I see the problems in academia as the same that exists in most of the mainstream media.
Those anti-establishment, anti-traditional values, and sometimes anti-America children of the 60's eventually put away their hookahs and beads and became productive members of the middle class but they didn't lose all that dogma. And eventually it was they who achieved senority in the news rooms and in academia and were mostly impressed by and hired people who believed and talked as they did. Conservatives were either mostly not hired or found themselves in such a philosophically hostile environment that they left and found other things to do.
And now the Left takes pride that they dominate in both realms and sometimes look down their noses at those on the Right who they see as less 'nice people' or 'less intellectual' or 'less well educated'.
And of course that perpetuates the problem and lopsidedness that exists. As George Will once commented based on that study you cite, the Left values diversity in everything but thought.