I do agree a lot more jobs available for youngsters in the 50's , all the more reason for them to get good qualifications.
If they are not prepared to work at school then of course they should expect they would have a lower wage job , but this is no excuse for violence .
There are two main factors , in my humble opinion to , cause problems like you have mentioned in the employment market.

1. Technology has changed the rules. Nothing can be done about this , you cannot put the clock back.

2. About 3 to 4 million immigrants let in by New Labour. They are in a lot of cases taking the unskilled jobs which are then not available to youngsters born here.