Which according to your logic is completely fine and fair, so why don't you summon the intellectual courage to flat-out say so here instead of hiding behind Asians' "belief"?
Racial diversity is more important than individual achievement, so it is just and appropriate that even if an Asian student does substantially better than a Black student on those academic standards judged by the university, the Black student should get the position. The Asian student is competing against other Asian students, not Black students. Universities shouldn't want the best achievers overall, they should want the best achievers of each race.
Yes, that means Asians will have to reach higher standards than Blacks. Jews will have to reach higher standards than Hispanics. Just be open about it--more like UNC and less like Harvard. And figure out how to pass whichever laws you need to to make it legal without relying on the whims of the Supreme Court.
Personally, I think this is largely misguided. Many Black children grow up in poverty, with terrible schools, role-models who don't promote academic success, and adults and institutions who don't invest in them attaining their potentials. (Children of other races also sometimes grow up under these conditions, albeit at lower rates.) If we intervene there, as the Harlem Children's Zone has, then guess what happens? Then we don't particularly need affirmative action, because we've fixed a lot of the causes of the disparities in educational attainment.
Thus, to me, affirmative action-style policies are depressingly defeatest. "We know how to help you excel. But, you know, we won't. It's kind of expensive in the short run, and we like to have extra money right now more than we care about you. But, whatever, we'll let you into Harvard anyway. Maybe you can catch yourself up, even though most everyone's better prepared than you. Sound cool?"
No, it doesn't sound cool to me at all.
(It doesn't look like the catch-up happened astoundingly well, though it would take a detailed analysis using data I don't have in order to know for sure. The disparity is maintained, though whether it's lessened by more than one would expect from typical regression to the mean is hard to judge. Here are the SAT scores going in to Harvard, as a rough proxy for academic preparedness: https://www.thecrimson.com/article/2018/10/22/asian-american-admit-sat-scores/. And here's the racial breakdown for GPA on the way out (note Harvard's crazy grade inflation, and click down to "Making the Grade") for the last year they reported on it: https://features.thecrimson.com/2015/senior-survey/.)