Discrimination didn’t magically end with the Civil Rights Act, either. American universities are still mostly good ol’ boy networks in all the relevant ways.
You’ll notice that most people arguing against DEI rarely perform meaningful analytics. Because when you do look at the data it tells the tale that the same centuries old systemic biases are still in play.
This is obvious to any adult in the room. But the benefactors of said biases do not want to acknowledge it since it lays bare their utter mediocrity.