Sounds like Ross Douthat is uttering much of the same critical spiel tossed around by the then prevailing establishment and sympathizers among those in older and boomer generations against the boomers involved in protests for Civil Rights, against the Vietnam War, and for greater freedoms to express themselves freely in various forms on campus*.
One thing I do agree with him is his approximate timeline where he cited the radicalism of the '60s changing over into a greater careerism/political apathy of many undergrads at mainstream colleges during the '90s era. This seemed to have extended even to some colleges with a long tradition of radical left political activism such as Berkeley judging by how one transfer student arrived at my LAC(Oberlin) in the mid-'90s because he complained “Berkeley has become too damned conservative and students too pre-professional” to be a good fit for him.
However, I’m not sure it’s necessarily the fact many such undergrads were vaguely liberal so much as apolitical or inclined towards being right-leaning as most of our childhood years did take place during the Republican era of Reagan and the first Bush administrations.
One common complaint among many classmates’ parents and older HS/college alums…especially those who were hippies or otherwise active/sympathetic to the '60s protests/counter cultural movements was that our generation(Gen X) tended to be much more conservative and/or politically apathetic than they were in their day.
And there were plenty of real-life Alex P. Keatons** during my HS years rebelling against their progressive/radical lefty boomer parents who enjoyed riling up their parents and progressive/radically lefty HS classmates. And they along with the rest of us who were children of the Reagan and Bush I administrations ended up being undergrads throughout the '90s and extreme early '00s which accounted for the politically apathetic or inclination to lean more right politically than those before or after us.
- I.e. Eradication of rigid classroom dress codes in most US colleges as opposed to the mid-'60s and before when undergrads can and were ejected from class for not wearing a formal suit & tie or female equivalent or for even merely forgetting to wear a tie as a HS classmate's father experienced as an NYU freshman in 1964.
** Alex P Keaton(played by Michael J. Fox) was the out and proud young Conservative son of two boomer parents who were active hippies during the '60s era on the '80s era Sitcom, Family Ties.