And in what way is this special treatment?

Companies use a variety of different metrics by which to determine which schools they should recruit from. "We want to increase our diversity" is a reasonable metric to use, and "recruit from colleges with an above-average percentage of people in a minority group we've chosen to view as important" is a reasonable way to accomplish that.

I shouldn't have to point this out, but diversity is more than just a buzzword. Increasing diversity on the development side improves the final product, for a variety of reasons.