I agree with this. I went to a private school because my family could afford it, and as valedictorian I got into every school I applied to and received full scholarships to most. The valedictorian of the public school didn't get any scholarships, not even to the local community college. Anyone who could afford to send their kids to private school did.

It's just a fact that people with more wealth have better socioeconomic opportunity than people with less wealth, not that they're more intelligent. This means better schools and better education.