The problem is, IMO, no parent wants to be the one who puts their child into a failing school to raise the standards for future children.
I live in an area where the state primary schools are some of the best in the country but the secondary schools have the highest truancy rates in the UK and each OFSTED report for these schools mentions poor pupil behaviour and results.
The reason seems to be that involved and supportive parents use the primary schools but opt out of the secondary schools to go private by hook or by crook.
The result is that, as the local secondary schools are undersubscribed, they are then 'opened up' to children in neighbouring boroughs where parental involvement/interest seems to be less.
It is cyclical. Poor attendance/behaviour and results mean that local parents will not choose to send their children to their local school.