Funding schools through property taxes is an easy explanation for that one. There are other factors, of course, but are there any other industrialized nations where public funding of education is directly tied to parental wealth?
Though if it wasn't for that it would be through a local school levy, or a fundraiser, or any number of other seemingly harmless methods of transferring money from parents to the school.
Even dumb ideas off the top of my head like "Wealthy parent A purchases 300 textbooks and donates them to the school so the school can spend that money on higher salaries for teachers" are probably legal ways for wealthy parents to supplement their local school.
Like a wise princess once said, "The more you tighten your grip, the more [wealthy parents] will slip through your fingers."
The real problems, whatever they are, run much deeper than local funding of schools. Focusing on funding is a red herring.
I'm not sure it's a red herring. It may be necessary, but not sufficient.
Why won't we switch to that? Well, most homes owe a significant portion of their value to "being in a good school district" and most such homeowners have made a leveraged bet of most of their net worth in that home. Such reform would mean destroying that.
It would also mean schools trying to apply the same resegregation filters most parents want, at which point governments would have to adapt their criteria to stop that, and the arms races continues.
This is, IMO, a very progressive idea, and I totally expected it to fail. What I didn't expect was how badly it failed in the one of the most progressive/liberal towns in the state: Boulder.
It seems that, while the people in Boulder talk about helping others, when it comes to potentially reducing the (granted, excellent) quality of the schools in their own back yard, they vote selfishly along with the rest.
Sad.