I think there are different groups of people, but I would say these reasons cover a lot of young people of all races from urban areas:
DISCLAIMER: Reasons does not mean 'justifications'. I think at the end of the day every person is responsible for their own behaviour (though the age at which this is true is debatable)
The materialistic culture promoted both in the general media but particularly in the media of young people. The life goal kind of thing is to have this lifestyle, to 'make it'.
Stealing from people and stealing from shops is seen as totally different. I would say that many people there would never DREAM of stealing from a person. 'Curry's can lose a few TVs'
Social mobility is very low, and those who didn't get a good education have no means to 'make it'. Being broke is seen as humiliating.
Children in middle class areas generally have positive peer pressure that ensures achievement in school i.e. it is the norm to attend university. There is a lot of low teacher expectations in poor areas, and against black children, which is all subconscious (have seen it myself through working in a school, with black boys in particular in lower ability groups than what is appropriate).
'Gangsta' rap imported from the US and Jamaica, where social mobility is even lower, impresses its ideas on the young people, and make them believe that if you were born in the 'hood' you have absolutely no choice but to sell crack, or steal, or whatever.
Police are obviously not popular as they arrest people over minor things like smoking weed, stop and search with no justification and are often rude, hostile and do not have any kind of understanding about the life these young people are living.
In these shops in their local 'community' they are often treated with disrespect, looked at as criminals, watched constantly or even followed all the way around the shop.
They do not like their communities and a lot of young people would state their aim is to make money and 'move out the hood'.
I don't think you can blame the parents. In a middle class area you have positive peer pressure and positive input from schools. If you are an average parent your child will not commit crime. In these areas you have to be an EXCEPTIONAL parent for your sons to not commit crime, due to the peer group.
Materialism with the 'more more more mememe' culture does not seem to be a problem with the middle class as they can afford to indulge it.
People keep saying 'you can make it with hard work', but that is much more difficult than it sounds, especially with inept parents. And I don't think we can blame 11 year olds for not working hard at school, as working hard in an environment where working hard is for 'neeks' (geeks) who are bullied, robbed and beaten up, is certainly not easy at all.
I am not in any way defending the burning of people's homes. I thought that was disgusting and totally incongruous with the other actions. I would imagine they just got caught up in the hype.