First, I agree with part of your sentiment. Not only is it financially and socially against the interest of citizens to allow private corporations to be jailors, it is also morally and ethically repugnant t choose organizations which maximize profits instead of those that maximize rehabilitation and minimizes recidivism.

I've had personal experience in this area. Although I've never been to prison, I spent a week in a county jail for a charge that I was innocent of and ultimately acquitted. In that short span, I witnessed just how broken the system is. Using the word justice to describe this system a tragic joke. The "justice" you receive is in direct relation to how much you spend on your legal defense. To me, it's a joke and a modern form of double speak. It's more accurate to call this system the societal stablizization system It blows my mind that people have faith in this system when people who have to rely on woefully under-resourced public defenders go to jail. The prosecution coerces you to take a "deal", which is usually sanctioned by the defender. If you elect to seek a fair trial in court, they take this deal off the table and retaliate by seeking the maximum possible sentence. It should not surprise you that when many prosecutors run for office, one of the things they tout is the number of years they have gotten people sentenced to. How can people accept widespread disparity in sentences for the same crime when the system has the word justice in it?

As a prisoner, many know that you are a source of virtually free labor. This is troublesome on its own, but when you are a source of free labor for private capital...we have a very precise term for that arrangement. This is also counterproductive because it takes away from prisoners a nest egg that they can use while to house, feed, eat, and clothe themselves while they go and look for one of those mythical jobs out there for ex-cons. If one doesn't have a place to sleep, food to eat, etc.. you literally have to make a decision to either go hungry and sleep on the street or you focus on base survival and take what you need.

It doesn't stop there because not only are you a prisoner, you are also a captive consumer to outside contractors/monopolists. The most notorious parasitic vulture out there is none other than Bob Barker. If you guessed that he sells travel sizes of the most basic toothpaste for $6, then the price is right! I'm not even going to go into the antiquated, exploitative system for making phone calls.

However, private prisons only house like 8% of the incarcerated. I'm not sure if you're trying to distinguish between private prisons or not, but any organization usually needs a vendor. And, boy, prison vendors sure have the taxpayer's best interest at heart. The fingerprint scanning machines are about 2x the size of those massive 4 foot tall copier/fax/scanners you would see from the 90's. I understand that it has to have a high degree of precision, but it baffles all reason when they spend at the minimum $6000 for a behemoth machine (that needs regular maintenence over time, which costs) while I own a phone that I paid $300 for that can scan all 10 fingers and it fits in my pocket.

I've already written too much, but the most despicable part was the prison's enforced racial segregation. I had heard a little bit about it before, but I wasn't prepared to travel back in time to the Jim Crow era where you are really only allowed to interact with people of your own race. That means, you have to take a shower with your race, watch tv with your race, eat with them, etc. So, instead of teaching or encouraging prisoners to get along with people different from them (the type of thing you need to do in the real world in the US), you are inculcated and degraded into an ignorant and antiquated relic from a mostly bygone era. I just wasn't ready to hear someeone say literally "Alright, you blacks over her. Mexicans, Hispanics, latinos or whatever over here. White people, you stay here

As a victim of crime, I understand the desire to see the assailant punished severely. But at the end of the day, you have to ask yourself would you rather that person experience at least just as much pain and loss as you did or would you rather have a system that focuses on prevention and rehabilitation so that society overall is safer and no one else has to go through your experience as a victim.

EDIT: This is anecdotal, so it may not apply to your area, but prison guards are some of the dimmest employees I've ever come across. 16 yr old drug dealing high school dropouts were categorically more articulate and could calculate basic math like 10x better. They make $43,000 on average and face the same amount of danger as a teenager working the overnight shift at a gas station.

It's sad that most of the public's interaction with officers, etc happens with patrol level police officers instead of people like detectives, administrators, and the like.