More recently I've heard the riots widely blamed on a "something for nothing" mentality. Celebrities, the National Lottery (copyright J. Major), game shows and the benefits system are all cited as examples of this corrosive cultural malaise, which allows an underclass to live in the lap of poverty on their grace and favour estates, generation after generation. Oddly, though, no one cites inherited wealth, such as that of, say, David Cameron; or inherited titles, such as that of, say, Prince William. On the contrary, the Government is committed to keeping inheritance tax low, and is wholly committed to the monarchy. Funny, that.
ETA: I've now seen some fairly plausible evidence that the above Cameron quote was invented. But I'm leaving it up, because its content (minus the bit about setting fire to the toilets) is true. Cameron and Johnson, with others, did "smash places up", around the same time Nick Clegg was committing arson in Germay (thanks to a_d_medievalist for the link).