I'm happy to send my kids to average schools, maybe even below average, if it's clear that the teaching is of such a quality that strong, supported children can succeed.
But some schools right at the bottom of the pile have long given up, and the day is more about firefighting and controlling outbursts, misbehaviour, children leaving classrooms and children who actually want to learn are forgotten about, sat in noisy rooms with teachers who can't be heard and suffering lengthy group punishments.
There's a line you have to draw. The school I want for my kids is in a mixed area, with a mixed intake, and it wholly supports every one, and achieves around 60-65% pass rate. Yeah, I wish it was higher, but I reckon kids who work hard will be OK.
However there's a school next door to me with a 20% pass rate and no kids get As or Bs. And I encounter them when they arrive at and leave school. And they are frightening. They hurled snowballs at me when I was pregnant and struggling on ice. They have beaten passers-by who have intervened when they have tried to help weaker students being beaten by bullies. There are acts of violence and arson frequently in the news. No matter how hard I imagine there are some teachers trying to teach well, and some students trying to learn, it frankly does not feel safe to sit in those rooms, with those students, nor can I imagine the days pass pleasantly with frequent police visits and the toilets being set alight.
You have to weight it up. Beyond a certain point, a 'school with a challenging intake but where everyone does reasonably well' becomes 'a hole'.