Unfortunately in our society it is still more likely that a black kid is going to have a tougher time then a white kid. So a school can reasonably assume that on average the white kid had better schools, more money, a more stable family, and better role models. In order to even this out they give a few more points to the black kid.
That's the problem with AA to begin with...it just masks the greater problem. Rather than trying to fix the educational system, the government gives a "pass" to people of a different race as a way to placate them. AA basically says "ok so things suck for you, but instead of making it better, we're just going to help the minorities lucky enough to go to college/grad school by giving them a couple of points on their application" And rather than questioning why whites have better educational opportunities (on the whole) than minorities, people of different races buy into this whole idea by checking off that box on their application.
Also in the grand scheme of things, AA benefits WHITE women over any other group when it comes to employment. Go figure. I'm all about diversity in school and in the work place. My high school was in the range of 40-50% black/hispanic. I watched a black kid that I knew very well, who grew up VERY wealthy, who had mediocre grades get into Duke. Most of the other black kids in my high school went to county college b/c they couldn't afford the cost of a 4 year college. Where's the justice in that?