I guess I don't agree with your idea that this is a reflection of the idea that it's a good thing to go after rich white people. The problem with analyzing college admissions to this point is that there's no one else to go after. By percentage, who else can you rag on? There's just no other demographic that's been going to college as long. In 2016 at least 57% of college students described themselves as white, which has fallen since the 1976 level of 84% [1]. And college has always been for the well-off, not the poor.

If you want to you could figure out how many white ALDC admits would get in if treated as African American non-ALDCs; I'd encourage you to then normalize across high school quality and expense, too. And looking at the lot of Asian-Americans in US college admissions is certainly important right now. For a quick peek, just look at Caltech's admits, since they have historically ignored legacy and race unlike everyone else.

But again, who else are you going to rag on if you're going to investigate the effect of legacy admissions and prof's children admissions? Due to the historic legal structure of the US it's just going to be really white. Fortunately for us ladies, men have daughters at a relatively high rate and we're allowed to go to college now so we can now benefit from unfair advantages too. (Again, it's instructive to look at Caltech, which did not admit women until the early 1970s and famously did not hire Emmy Noether because she was female. The percentage of women students has risen steadily as access to math and science education has become more available to the girls of the college-going classes of the US.)

[1] https://nces.ed.gov/fastfacts/display.asp?id=98