should all juvenile crime be treated in this way - if not, why not?

This case is hardly typical of juvenile crime, and I was discussing this case, not 'all juvenile crime'. They knew just what they were doing, and how wrong it was - that much is obvious. Their release and anonymity posed an undeniable danger to society, and was ill-advised. They are no longer ten year olds, they are adults who more or less got away with what they did without really answering for the consequences. It's not about vengeance, it's about protecting society from dangerous nutters.