After years of looking at this phenomenon your post finally made something click in my head. We've decided that birth rate is the primary measure of your merit. The more babies you have the more people that look like you we're going to allow into universities and good jobs. So weird...
Perhaps it may end up that way in some cases, but that's not the intention. Art & Music universities often feel that diversity increases creativity, and they are in the creativity biz: the more (perceived) creativity that flows out of the U, the more they can hike tuition.
Having one group heavily- or over-represented may be seen as going against that goal. It's not necessarily personal against Asians. They may not want too many whites either.
But proportional to birth rate is arbitrary. If we decide there's 10 "races" why not try to force representation to be at 10% each? Wouldn't that be even better for diversity? If your race has a lower birth rate maybe we should give you a little boost by making sure you get a college education and a good job.