That's such a tired old argument. I don't have kids, why do my taxes go to schools? Because it's a requirement for a functioning society. The current system isn't good either, but we need to start by ensuring everyone participates in the healthcare system, use it or not.
Education taxes aren't for parents; they are for kids. And young children cannot yet plan or provide for their education.
Contrast that with retirement, healthcare, life insurance, auto insurance, etc. These are all decisions made by people who should have the right to choose to participate.