It's worse than that—if public schools don't offer the kinds of advanced courses that wealthy parents expect their kids to have, the wealthy parents don't just shrug and say oh well. They pull them out of public school and put them into private school or homeschool or get them a tutor. It doesn't matter why a public school is inadequate (whether it's because of policy like this or simple underfunding), inadequate public schools invariably increase achievement gaps between socioeconomic classes. There's no other possible outcome. There's no world where everyone gets held down equally.