It turns out it's much easier to achieve equity by pushing people down (no more AP courses for anyone) than by lifting people up (getting more black and latino students into AP courses).
The "ruling" class were angry that the plumbers' kids weren't paying a full 4yr of dues to the state colleges so now they're making it so you need to go to private school if you want to get a head start at college gen-eds. And they sold the idea to the masses in the name of making all the animals equal.
I'm being cynical. More likely the people responsible just don't know or care and pushing everybody down is just the easiest way to appease the pro-equity crowd.
This is central to the whole problem with this concept of "equity". If the implementation, as you say, _at all_ involves cutting someone down, then it's morally bankrupt. Who decides who gets cut down? Does the person being cut down have a voice? Are they told how they're supposed to feel about it? Is that not creating a newly marginalized group? This will lead to lots of division, and understandably so.
There's a lot of truth to the adage "two wrongs don't make a right". Equity seems to be about saying that everyone should have the same outcome, by force if necessary.
I should note that "equity" need not mean "equality of outcomes", but when pressed for how one evaluates "equity" far too many proponents fall back to "equality (and proportionality) of outcomes" in practice....
I fear that the concept of equity presents a real possibility of a race to the bottom if we're not careful to prevent a Harrison Bergeron situation. That doesn't mean I think we should avoid equity, just that we should be cognizant of the potential pitfalls along the way to determining the exact implementation.