I did look it up. You should read further. There were a few Jewish philosophers who escaped Nazi Germany and wrote some stuff. Your "Frankfurt School". Never went anywhere in the real world. Most philosophies don't. Education systems are chartered with teaching people about ideas and philosophy is certainly a part of that charter. So, you are all about censoring education to teach what you approve of.
What you are parroting is a fascist-white supremacist-alt.right made up idea that those five or so academics spawned an evil multiculturalism that is somehow imposing a monoculture on the world. Ridiculous and contradictory but useful propaganda.
I'll repeat. As long as unequal opportunity exists, then enforcement of civil rights laws is necessary. What your Rubin dude and others are whining about is enforcement of civil rights laws to address inequality in this country.
Yep, the alt.right, KKK, other white supremacist groups are murderous sons of bitches. Our first amendment requires the government to allow them to take their hate speech to the streets and intimidate minorities. A black or Jewish child should never experience fear from people brandishing and marching with Nazi flags or other white supremacist regalia shouting death slogans at them without those children also seeing significant opposition to their speech. The government can't stop them so the good citizens of this country must.
Don't even think of using the slippery slope argument about this. Those hate groups preach death and marginalization of minorities. Fair minded people have every right to stand up to them in numbers that cause THEM to quail in fear. I was at a counterdemonstration in Portland last year. You bet those few assholes hid behind the cops when they saw how many we were and what we were prepared to do to them if they set on foot outside the protected perimeter. That's what I wanted the kids to see. We were peaceful, we let the police maintain order but there was no question about those assholes leaving police protection to march in the streets of my city.