I'm not speaking of the very principle, I am speaking of the implementation that leads to prison population 8x that of other countries of comparable wealth.

edit: just google about prison guard unions lobbying for harsher sentencing. Do they think harsher sentencing is a net social benefit? No they don't, they think it is a net benefit to prison guards.

A lot of debates boil down simply to different groups pushing for things that benefit said group at someone else's great expense.