Human rights observers have repeatedly concluded that the U.S. prison system is unnecessarily brutal. Guard abuse, rotating solitary confinement and even extended solitary confinement for decades, poor psychiatric care that leads to inmates being shuffled into the solitary confinement system... it's not just cruel, it's stupid and unnecessary. The U.S. has one of the highest recidivism rates in the world. Taxpayers are spending billions on programs that aren't delivering returns. We've long since passed the level where our incarceration rate is delivering any additional benefits for crime rates, and the cost has been the social isolation of individuals so that they are almost guaranteed to commit crime in order to survive or just out of frustration or anger.
Treating criminals like inhuman monsters to corral isn't just hypocritical given how many war criminals are running around without any consequences and given how rarely white collar crime sees any punishment, it isn't just inhumane, it doesn't just threaten our democracy and our status as a city on the hill. It's also just stupid. Worse, it actually undermines the brutality of the crime itself.
Successful programs teach the inmate that the punishment was committing the crime. Jail is how they get through it. There's no punishment that you can concoct worse than making someone face what they did to someone else. Coincidentally, that's also the best way to reduce recividism and bring people back to the community when they are released.
We have to be smarter and more enlightened than to allow the heat of the moment and the temptation of the monkey brain to lead us to smash our fellow man. It just doesn't work.