This is basically what I was trying to get at with my original comment - I think you did a better job of expressing it.

At some level you have to have to have something to show for your potential - otherwise there's no way to choose between candidates. Every single metric will advantage those who had the time, money, and resources to invest in developing academic aptitude. There are a small group of people who get by on developing musical or athletic aptitude but even those require time, money, energy, resources.