You just state it more concisely :)
Prison isn't something we should want in a society, but actively reduce, even if we never realistically achieve it.
Believe it or not, a society with 300 million plus people can do many things at once.
Human resources aren't really fungible. Big brains spent on improving education of children can't really be reallocated to spend on cancer research or other part of medical science, not without extensive training at least.
So too we can spend on psychological, social services, and welfare which is what we probably need to reduce crime and overall human suffering to a more manageable level. Hopefully, the improvement to societal health means more resources are available that can be then reallocated to tackle the remainder of human caused suffering.
It's flat wrong.
I would put harm prevention above penance. Penance is just a tool that promotes caring, ideally before said harms become permanent.
What we ultimately want is that people who don't murder. Also, as someone noted, you probably reading too much into it.