They want to manipulate the outcome in pursuit of "equity," but doing so with differential scoring criteria is to highlight the very differences they claim don't exist.
The demonization of test scores in academia is evidence of this. Affirmative action in University admissions has been around forever, and that's just a form of differential scoring. Not good enough. So now we get rid of grades, leaving group identity rather than performance as the metric for measuring worth. Ugly stuff.
As soon as you realize that the whole philosophy is corrupt, and the leaders of the movement know it, understanding the policy gets a lot easier. There's a reason the thought-leaders on the left have all but completely stopped engaging in debates with their counterparts on the right. They're lying, and you don't promote a lie by giving your opposition a platform to call you out on it.