Sorry Highlander to hit a nerve (if I did) - if my original post came across as flippant I am sorry.
The school I went to was truly comprehensive - it was a rural comp, it had one of the largest geographical cathcments in the country. As the alternative were the local private schools (which were crap, frankly), there was a real mix with chidlren of all classes and underclasses mixing together.
It was a crappy school (still is) but it was a true mix, and although loads of kids achieved nothing, there were also loads who did well.
Of course not all kids suit schools like this at all, Highlander you would obviously have done better in a smaller, less volatile school. And of course I would never recommend just blithely sending your child to school to validate your social preferences. Just that don't necessarily right off a rough school, it may well suit your child to go there.
I have had to do exactlu this - my dd used to go to a very highly regarded selectve school in Cheltenham. She was horribly bullied and made herself ill such was her fear of school. And this was not roughness - this was a brilliant school, near enough 90% A-C at GCSE, places there were really coveted. This was just snidy verbal nastiness.
i had to get her into another school, it was very hard as we live in Gloucester, where you have 4 grammars and 5 comps. The 4 grammars were a no no - the waiting lists were huge, and being dyslixic dd would not have passed the entrance exams (gloucester has an obligatory 11+). Out of the comps, 1 was catholic (over my dead etc), 1 was all girls (wanted mixed), another one was all boys, another had no 6th form, and the only one left was a pretty poorly regarded comp in a rough area which had less than half teh success rate at GCSE. I dreaded sending dd there, but the alternative was to send her miles away into the Forest of dean (which she didn't want).
She LOVES the school. She is far, far happier than she was at her old (supposedly better) school. I go round telling everyone that this supposedly sink school has been an absolutely briliant place for my dd.
The discipline at her new school is far stricter (it has to be, dd says that some kids do kick off) and although the school may not suit all kids, it does suit dd.