In favor of affirmative action, one argument that doesn't even require comparing "equality of outcome/opportunity" between individuals, is that the university should have some say in the makeup of its incoming class, and should have a right to minimize its homogeneity. You might argue that race is not an attribute upon which homogeneity can legally be measured, but that won't change the fact that it's a proxy for life experience. All else being equal, two people of the same skin color will have more in common with each other than two people of differing skin colors, by definition of "all else being equal." So if you're an admissions office building a freshman class with the goal of optimizing the learning experience for each member of it - which includes the learning experience from interacting with classmates - then which would be the better outcome: (a) one where everybody looks the same and has a large degree of overlapping life experience simply due to shared skin color, or (b) one where each student has a chance to meet another student with a completely different upbringing from their own?

Now, I'm personally against race-based affirmative action, but I also recognize that a freshman class composed entirely of students of the same skin color is not an ideal outcome. The fact of the matter is that everyone in that class would have some degree of similarity in their life experience, because their skin color is unavoidably something upon which people notice and discriminate (e.g. dating preferences, subconscious stereotyping, etc.).

I think the ruling also understands this, and it emphasizes that university admissions offices are allowed to consider upbringing in their evaluations of applicants. So if they want a class with some poor kids and some rich kids, and some musical geniuses and some athletes, and some boys and some girls and some gay people and straight people, then they should be allowed to consider all those factors. And perhaps naturally this will result in a class with a heterogenous racial makeup. But what they can't do is work backwards from that, and assume the racial composition of their class must be a proxy for all the other axes along which they want to minimize its homogeneity.

I'm not sure about the underlying logic, and I think it's possible it just shifts the problem - because there is always some human element in admissions, and I'm not sure it's possible to minimize group homogeneity along an axis without discriminating along that axis when evaluating an individual - but I do feel that explicitly discriminating evaluations of individual applicants based on race is clearly wrong.

As a final point: It's also worth considering that even when discriminating on race, the universities were still discriminating along other axes arguably not "in the spirit" of affirmative action - for example, a black person from a boarding school would receive more "benefit of the doubt" than a black person from a public school. And isn't that institutionalizing whatever biases led one applicant to a boarding school but kept another at home? Maybe a positive outcome of this ruling is that it will force universities - who rightfully strive to minimize homogeneity of their incoming classes - to actively seek metrics for measuring diversity instead of lazily depending on skin color while ironically institutionalizing the same biases that affirmative action sought to eliminate.