You're wrong. The whole system should be based on crime prevention, not punishment.
There should be better predictors of how likely a person is going to repeat the crime and keep him locked up for that amount of time. Also, predictors of how likely it is for someone to make their first crime, so it could be prevented in the first place.
I'm pretty sure that it's possible to predict future criminals from their Facebook data etc, and just send those people somewhere else where their environment matches their behavior.
There should be better predictors of how likely a person is going to repeat the crime and keep him locked up for that amount of time. Also, predictors of how likely it is for someone to make their first crime, so it could be prevented in the first place.
I'm pretty sure that it's possible to predict future criminals from their Facebook data etc, and just send those people somewhere else where their environment matches their behavior.