Where do you think the people in the entertainment and media learns those values.
If you trace the history where all this progressive values started, it all started in academia, among the intelligentsia, in the late 19th century.
To a considerable extent true.
However, the producers of culture have always been neck and neck with the academy in this regard. In fact, the initial leaders in the attack were the avant garde of high culture: music, arts, literature. I think it moved from there into the academy, although there was obviously a lot of overlap. The Impressionists and later the Surrealists were not for the most part in the academy.
The story since has largely been one of the attack moving down market. The avant garde turned out to be exactly what it claimed.
It’s a symbiotic relationship. Media/entertainment work at changing the popular culture, the academy at providing high-minded rationales for the changes.
I think it’s largely a chicken and egg question. It’s not like most creators of popular culture are simply regurgitating what they learned in college. They’re all part of the same anti-American (actually anti-Western Civ) subculture. Although it’s very nearly become the dominant culture at this point.