but there's no job that pays as good as drugs pay
Interestingly, that is quite possibly not true for low-level runners and street dealers. The writer Tony Thompson wrote a very interesting book (whose title escapes me at the mo, unfortunately) about gangs and reported some research and statistics showing just how little the rank and file got out of it (less, in most cases, than the kind of unskilled jobs for which they would be eligible). That is why the gangsters need to inculcate the kids into the gang culture early: few people would live this life as a logical, better choice than mainstream life. They need to be indoctrinated, cajoled and threatened (and of course, generally speaking they need to have family lives so disastrous that the gang life is preferable). The chances of injury and violent death are high, as is the prospect of someone coming up and taking away from you all you have earned.
I don't think that the disturbances are a response to racism or deprivation in the way they were in the 1980s, except in the sense that in part because of those things, the people doing it have or feel they have no stake in wider society, so they don't care what harm they do.
There seems to be a very macho gang culture at work here, with boys and men effectively holding the rest of us (including their own kith and kin and neighbours) to ransom while they get their kicks and their TVs. It's a smash and grab and a power trip rolled up into one very exciting, adrenalin-fulled package.
There will be a reckoning, when police act on the CCTV and intelligence and all the tweets and messages to make arrests. A lot of the rioters are so young the idea of these kind of consequences don't occur to them. In the meantime, stealing from looted shops is not a capital offence, and we need to keep a sense of proportion. That said, I hope the arsonists get the very long sentences their actions deserve. Arson is terrifying.