“Monocultures suck. It's hard to know how many of the stories about ridiculous stuff happening on campuses to believe, but even if a small fraction of them are true, these are clearly no longer places hyperfocused on learning.”
It starts with negative priming. Though he has not and will not do any work to actually suggest colleges are monocultures, he throws it out there. Then he invites you to think of negative stories, and suggests some of them are probably true. In a complete non-sequitur (it must be, because he has not actually defined a premise, just asked his audience to imagine one), he provides a conclusion. But even there, to deflect criticism he moves the goalposts, implying that to be successful, colleges should be “hyperfocused.”