I agree that riots come and riots go in Britain, but I don't think that should be a reason for complacency, especially in light of the reminder from upthread that statistics on education show so much of the 'best of' and 'worst of' and have consistently since the dawn of universal compulsory education. Maybe a tendency to riot is part of the 'British character', or maybe the tendency is fueled by the perception of 'them and us' that existed before the establishment of the educational system and endures because the lasting inequalities of society are still mirrored in how schools operate, what they expect of students within their walls, how the system seems to work like a massive shape sorter.
OTOH, where are the parents in all this? An old friend from the US taught in a rough school in a really rough area and left after three years. He got tired of providing out of his own pocket paper, pens, pencils, markers, gloves, hats, winter jackets, socks, morning snacks. At first he made the mistake of letting the children bring the writing supplies home so they could do homework, only to have the children turn up in school the next day without either homework or writing supplies; to his shock, the same went for the winter jackets, and in a region famous for its harsh winters. The jackets and hats and gloves were used for playtime only. Over the course of his three years he had four parents turn up for parent evenings. He said the one thing parents and unions and educational administrators alike could never, ever say was that a lot of parents are feckless idiots. It was the elephant in the room, and the difference when he got a job in an area where parents cared was all the difference.