The problem with understanding the riots is that people are seeing them as one thing, when in reality there's several factors at play. The riots kicked off when police interrupted a peaceful protest regarding a man who was shot by the police (the facts surrounding this incident are not yet clear, but the police have already being caught lying about it). Since then they've escalated. Different people are involved in the riots for different reasons - some are (rightly, in my view) pissed off with years of neglect and heavy handed and racist policing. If you have no education, no chance of getting a job, and have been brought up in a world where violence is endemic and the only role models are vapid celebrities espousing mindless materialism, then you might as well riot, you'd be stupid not to. What's gonna stop you - prison? Prison isn't much of a deterrent if you already might as well be living in one.
And then there are the looters, quite a few if not most of whom are from more fortunate backgrounds. These arseholes are just petty criminals or opportunists, and their behaviour is inexcusable. Though going by past form I suspect the extent of the looting is being exaggerated by the police and the media, which is handy for the powers that be as they're distracting people from the real issues. British people love nothing more than a good old moral panic, so there's lots of hysterical calls to send in the army. It's only a matter of time til someone seriously suggests nuking the site from orbit just to be sure.