> This kind of assumption about prisoners is unhelpful.

It is a category error to call my statement helpful or unhelpful, since it's not my intention to help further any kind of agenda other than basic realism.

People, when they sit down in a bar, want some assurance that the person sitting next to them didn't get into a fight and smash a broken bottle into their neighbor's face. People taking their kids to school would like to know that their teacher didn't sleep with the kids. People sleeping in their homes at night would like to know that there isn't someone breaking and entering into their homes. People saving for their retirement would like to know that someone isn't running off with their pension. Someone running a business would like to know that there aren't burglars walking around that break into shops at night and steal their inventory. Everyone wants those who do this gone, gone from the group. Some may also want them punished, but I'm not being emotional here. Others fantasize about reforming people, when there is scant evidence that this is possible, but one way or another, society needs to purge itself of its criminal classes.

Note that not all of the above are "violent", but for society to work there needs to be cooperation, and for cooperation to work there needs to be trust. In order to maintain a steady state in which you can trust your neighbors well enough to be part of an advanced high-trust society, certain people who abuse that trust need to be removed from society, because not everyone is or can be trustworthy. In fact, it matters not at all who they are or why they did what they did. All that matters is their impact on social trust and their suitability for being part of the cooperating group. Hence my suggestion that we try to find some other group for them, rather than locking them up in a little room.

If you do not do that, you simply lose the high-trust society. Now there are men with shotguns guarding the entrance to every store. Bars around every window. And the whole society becomes a type of dysfunctional prison for everyone. Enormous costs are borne by everyone when we lose social trust, and it is the desire to avoid these costs that is the reason why we kick people out that we no longer trust to be peaceful, law abiding members of the group. There are many societies which don't have this trust, and very few of us would want to live there. There you often see the wealthy hiring their own private security and maintaining their own separate little bubble while everyone else is subject to the vagaries of a low-trust society. As the US becomes more "liberal" in attitudes, the same thing is happening here, except home prices effectively segregate into bubbles of high and low trust. Gated communities are becoming much more popular.

Those of us who still believe that a high trust society is possible in the US value being able to walk down the street without being assaulted, or that we don't need to live in a gated community with constant armed patrols, we don't want to program our cars to avoid low income areas. And this luxury should be afforded to everyone, not just those who can afford to self-segregate into high income bubbles. But in order have a high trust society, we have to expel a certain subset. It doesn't particularly matter if you don't like that this is a basic trade off.

> Not everyone who goes to jail is "dangerous"

There is a huge focus on violence, as if it's OK to say, burn down buildings, loot pension funds, or break into homes as long as no one gets hurt physically. The arsonist or conman need to be removed from a cooperating society just as much as the man who assaults people in bars. A lot more than a lack of violence is required in order for cooperation to be possible. Before deciding whether theft should be grounds for removal from society, go to a place where theft is very common and see how you enjoy living there. Look at the enormous security costs that must be paid by everyone. Look at the suspicious treatment everyone receives. Then decide whether removing people who serially steal is a worthwhile goal.

Now in terms of whether our laws have this right, that's a question for a debate on judicial reform, not prison reform. If you want to make the case that a certain type of crime doesn't warrant a prison sentence, that's fine by me, but IMO this is off-topic.