Earlier quoted context omitted.
I agree there's a lot to be done to reduce the number of prisoners. But at the end of the day, what do you do about members of society who greatly harm others? (murder, rape, etc)? I can't think of any effective solutions which aren't prison, death penalty, or prison-disguised-as-something-else (like a hospital). Maybe exile? What's your philosophy in those cases?
The way I see this is, prison should not be taken lightly. The cavalier attitude of simply shoving addicts into prison glosses over the gravity of using this option. There are appropriate use cases for prison, and violence in prison will be inevitable. The very least we can do is take that more seriously, and stop shoving addicts into the same place as violent murderers.
Isn't this already partly achieved by the delineation between low security & high security prisons, as well as delineations within the same prison complex (general population vs SHU)?