[Kizzy]

Maybe the us and them reason is one issue, however private schools are covers for tax fiddles as many are given charitable status I'd say this is a reason too.
It would make it a more level playing field with regard to university entry.
All that said I can't see how it will work, rich people are willing to pay for education that's not going to stop. As long as all the loopholes are closed I can't see the issue.