The whole comprehensive system is dragged down by the financial, spiritual, moral, educational and professional cost of the huge number of total wasters in the student body. Those who disrupt lessons, ignore teachers, distract students, talk back, waste time, make paper aeroplanes out of worksheets, dawdle in late, don't bother to do their homework, don't come equipped, chat and fidget and generally make no attempt to learn. They are utterly selfish and just tink of nothing but enjoying themselves.They are pandered to and spoilt, offered endless chances, suck the system dry of money, time, energy, and resources. Teachers are held responsible for their imbecilic behaviour, and grind themselves into dust trying to work to change behavior which is under someone elses control entirely.
This is why I support grammar schools. It gives the top 25% the opportunity to get away from these yobs, and and incentive to behave well, and keep behaving well, as a grammar school student needs to maintain certain levels of behavior and achievement to remain a grammar school student.
So overall, the poor behavior goes down. Because a grammar school place is an incentive to behave properly, and so some bad behaviour improves.
In a comp, badly behaved pupils have nothing to lose. That changes in a grammar system.
And a large number of students can get away from the poor behaviour too. Of course there is some bad behaviour in grammar schools, but it isn't comparable.
So less bad behaviour, more learning, and fewer students affected by bad behaviour in others. Whats not to like??
Of course it doesn't solve the problem of having to put up with bad behaviour in secondary modern classrooms, but it doesn't make it any worse either.