The government wouldn't buy old warehouses, churches etc to just build schools to accommodate an influx of pupils whose parents would rather pay for them to be educated elsewhere.
There are many ideals on this subject, without doubt. And many of them are wonderful.
I'm going to say something which won't make me popular but it's another way of looking at it (I think).
I know of many parents who send their children to private school who really begrudge having to spend the money.
They already financially contribute a lot of their gross salary to the tax man, some of which gets spent on state education. However, they don't feel the state schools available to them are good enough for their children so deem it necessary to privately educate their dc.
It isn't just about wanting better teachers. It's also about better pupil to teacher ratios, higher levels of behaviour standards (as other posters have said, disruptive children are removed swiftly).
I had a choice of 3 private schools for my dd. The first one was the prep I went to, I found it far too military and formal. The second's religious values were too high. The third that I have chosen is wonderful. It's family run, has a family community feel, has good ethics and the children all seemed very confident, happy and polite. It doesn't get the best academic results compared to the other two, but it encourages a strong work ethic, a wonderful involvement with the local state schools, a very low tolerance for bullying and strong morals for acceptance and hard work. And their statement is "Every child has a talent. We must help them find it and use to the best of their ability."
The state schools in our catchment area don't give me any confidence that they can do a fraction of what I would expect from a school. And for my dd I should give her what I feel she deserves and if the state schools that I do financially contribute to can't offer it, than I shall try my hardest to provide somewhere I can.
I do think it's a shame that the minority seem to be the ones who ruin it. I'm confident in saying that if there were more parents supporting their dc educational/emotional needs, there would be less disruption in classes so the teachers could focus on teaching not babysitting, fewer people would choose private schools.
But ultimately why not teach your children to strive for better to have the nicer things. Surely that's better than telling them they'll have to 'make do' because 'what's the point?'
On a separate note, it still wouldn't work with the authorised absence, the "richer" pupils parents will just pay the fines/happily pay the extortionate prices in the holidays/move abroad/home school.
Nataleejah I think you seem to have confused this post with a question of how you'd run this country if you were PM. I don't dispute a lot of the principles on here, but it's the reality, practicalities and sociology of it all as it stands now.