And by that same token, anyone that does not have children at all shouldn't have to support it either. Then what you have is people paying for their own children's education. If this is to be the case, then why pay taxes at all? Cut out the middleman.
The real problem here is that many people truly cannot afford to pay for their children's education. Which brings up the point of "why are they having children if they can't afford it", and opens another huge can of worms.
Let me put it another way. If a tax paying citizen is paying for a quality education for his/her child(ren), these parents should qualify for a serious tax deduction to compensate for it. What they are essentially having to do is pay twice for educating the same child.