Hell with the law, let's go for revenge
The law is supposed to apply to everyone evenly, and you are supposed to be able to know what the laws and punishments are. There didn't use to be anything about adding extra punishments on after the offence was committed. There is no provision in law for this.
The standard punishments are laid down, and the magistrates and judges can vary them according to circumstances. So they will already have taken into account all the background to each individual case and set the penalty accordingly. Cutting the benefit is then an extra punishment *after* everything has been taken into account.
It punishes those who were out of work and rioted, but not those who had a job and still rioted.
It takes no account of individual circumstances, family members, etc.
It leaves people with no way to survive except to commit further crimes.
The comments I've seen don't have any reference to reform, rehabilitation, deterrence, or even punishment. They're all about REVENGE. Do we really want such a fundamental change to our legal system?