Agreed 100% (it's also for punishment). Yet, what do you do with people who've spent years locked up, learning to be better criminals, have no education, no job experience or training and now probably have gang affiliations when they are released?
This isn't a soft of crime position, it's a reality.
Society needs to be protected from criminals and this includes those who come out of lockup better at their "craft".
Right to carry, castle doctrine, stand your ground, and self defense immunity laws seem to be working pretty well.