There are a lot of young lads from chav-infested areas that are set up to fail academically. Their parents don't put a huge deal of importance on education, the dad typically works for a building firm and the mum is a stay-at-home - neither of these roles require any real level of academic intelligence or success to get into, so the parents don't see it as that big of a deal, as long as the kid is going to school and learning how to get on in life then that's all they care about.
I do sometimes wonder, though, if these people are any worse than the middle or lower-middle classes, with the parents being overly pushy on their kids to pass all their exams, with the kid growing up under pressure and feeling like they're going to bring shame on themselves and their parents if they don't excel, which is probably why mental health issues are rife in this group of teens, then eventually settling on a £25k a year desk job while the chav kid who did nothing at school ends up on not far off twice that much as a scaffolder or some s***.