Oh Dear Aeoline, I'm sorry if I offended you. It was merely observation from a career on both sides of the public/private divide.
Just to clarify a few points. One school I worked in, the kitchen staff were, almost exclusively, recruited from the usual pool of itinerant Kiwis and Aussies. Without exception they were all graduates, several with more than one degree. It wasn't unusual however for the teaching staff to have a HND or less. Granted it was a boarding school in the wilds where retaining staff was difficult at best, but I've witnessed one of the kitchen hands being roped in to take the Economics lessons when the regular teacher went ill. The kitchen hand had an undergraduate degree in economics and was a qualified accountant. The regular Economics teacher had a HND. Neither had a teaching qualification. The fees for that place were astronomical.
Student's raising their hands in exams, asking questions (I've seen that in both private and state schools) but only in private schools have I seen the questions being answered.
Getting children statemented is not a way you manage children out of a school, and to suggest such exposes your ignorance of the issue. Statementing in excrutiatingly difficult to do. The LEAs fight tooth and nail to avoid statements as statemented students carry increased funding. It costs them money. From the school's perspective, statementing is a good thing. It means there is extra cash (however little) to actually give the support students desperately need.
I'm not sure where you got the idea that I think "Private school children all take drugs" from. They were rampant everywhere I worked. Granted, you offered a better grade of class As in the posh schools, but you did have to put up with being treated like the servants.