Nobody who was genuinely good in his or her academic field and had something interesting to say would be happy to spend his or her career saying it to a bunch of over privileged children. You're getting the old duffers who just want to pontificate in front of a captive audience
You are probably quite right OriginalSteamingNit. In my own case I spent most of my life as an academic in research and teaching in a university
(university teaching was second to the interesting things I researched and had to say). However, as a second career, saying my interesting things to a compliant and receptive audience in an independent school is preferable I can assure you to trying to tell those things to a bunch odf spitting, biting, foul mouthed, obscene pupils in a comprehensive school. I did that for sometime before moving to an independent. Whilst I could " hack it" and didnt have problems, I had more self respect and more ability that to accept that I should have to do that everyday.
Those you need to look closely at are not the old duffers in independent schools who have come from academic backgrounds but ask why it is young teachers in state schools spend their whole lives putting up with that abuse and then try to make a virtue of it here on mumsnet.
I think we are getting close now to answering the original question about what is the truth concerning independent schools. Such schools have teachers who know their subjects, who are experienced, who do not tolerate abuse of themselves or others and that is why the learning environment is improved.
I removed my DS from a state primary school after a couole of incidents. I do not want my child being pushed, smacked , kicked, spat at, or called foul names. Neither do I want him here repeating that behaviour. That is not the fault of the teachers necessarily but that is commonplace in many state school classrooms - and it gets worse as the pupils get older. I do not want my DS subjected to that. That is the truth of state schools.