I was a state school teacher who sent my son to private school as I wasn't happy with the village school.
The problem for me is the patchiness of the educational spend by the government. Each child should get the same amount spent on its education from the public purse, but this does not happen. There are regional variations which come down in some cases to whether the LEA is Labour, Conservative or Lib Dem. You can find a £500 variation per child between some authorities, and if you multiply that by the size of the aver age comp of say 1400 students, that is a lot of money.
If the standards were the same all over the UK then yes, I'd be happy to send him to state school, but they're not. I paid to avoid disruption; to get more sport; to have teachers who knew who he was, not just a face in the corridor; for people to be able to tell me accurately how he was doing; for ethos and to have reinforced the lessons in manners and courtesy he was learning at home. The state system does not provide this by any means, and I know, as I taught in it.
No-one is saying that parents who use the state system are spongers, or that they don't pay tax, but those who use private schools are saying that they don't feel that the state provides value for your money. Just as I wouldn't go back to a shop that had provided bad services/goods, I won't use the state system for education until it is fairly funded and better organised.
For those who were talking about levels of income tax, yes those worse off do pay more income tax (thanks Mr Brown), but those who are higher paid, do pay more in NI, which is effectively raising their rate of tax to all intents and purposes.