1. High schools that tend to send high numbers of people to schools with acceptance rates less than 20% tend to be dis-proportionally represented. [1]
2. High schools that send kids to good college are more expensive (either inherently, or because they're in an expensive area).
Combine these two and you see the perpetual unfairness of education. Not to mention that MIT and other 'elite schools' barely teach well anyways. Picking kids who were already predisposed for success is not education. Unfortunately, many disagree.
A real school would have 100% of their kids admitted at random and then, through some criteria, show how they created an environment that allowed those kids to succeed. This contrasts with the current system, which is basically survivorship bias anyway.
EDIT: I just want to add any many of these elite schools (high school and college) only recently began to admit women and minorities in particular.
[1] Some schools with high amounts of kids going to "elite schools"
- Stuyvesant
- Boston Latin
- Brooklyn Science
- Brearly School
- Spence School
- Harvard-Westlake
- Lowell High School
- Saint Ann's
- Andover