Affirmative action, lol....
Perhaps affirmative action was a poor choice of words. I know that when I was applying to colleges, sports was specifically mentioned as a way to increase the diversity of the student body. It wasn't mentioned as increasing the diversity in terms of race, just that they wanted a student body made up of people with a variety of backgrounds and a variety of interests. Thus, ability to play football, or ability to play the tuba, or a host of other abilities made each student different, and thus created a diverse student body, and thus an atmosphere much different than if admission were based solely on academic ability.
I still believe sports has served this purpose, either intentionally, or unintentionally. Many people have come to college as a result of sports who otherwise would not have, and have benefited from the education by having successful non-sports-related careers.