That's true for some of them. There's also a very large number of people in prison who are legitimately good people, but made a mistake at some point or got pus

That's true for some of them. There's also a very large number of people in prison who are legitimately good people, but made a mistake at some point or got pushed into a situation where they didn't have many good options. There are plenty of people who have no desire to commit any crime and won't once they're let out. A big problem is that prison is a black hole that's hard to return from, part of which is due to society's perception of everyone who gets locked up and the mental wasting away and lack of development once you're in there.