I don't really know if I agree with the premise of this essay, mostly due to its deeply religious argument. Beyond its intense spirituality however its message is quite clear- the writer considers prisons to be a horrific phenomenon, and because horror is a reaction of morality, a morally unacceptable phenomenon.
The writer goes on to emphasize that prisons are morally unacceptable, but also importantly the normalization of imprisoning humans to be morally unacceptable.
The author probably only finds confinement-as-punishment morally unacceptable because he believes that just punishment will be meted out in the afterlife anyway. If you take away the assumption of religion, there's really no argument left.
If he's appealing to Catholic social teaching and using that thinking, he's definitely missing the point.
No proper Catholic would think, "We don't need to punish people now because they'll get theirs in the afterlife". That is absolutely not a Catholic view for a number of reasons.
I believe the discussion on the morality of making imprisonment the default choice is pretty interesting:
"But we are not merely allowing the abomination of the prison. We are promoting it (and in popular culture and politics, romanticizing it). And in the case of the very limited number of those with deeply disordered desires, we are taking the tremendously difficult task of healing, a task best addressed locally, in families, neighborhoods, and communities, and elevating it the level of the state, where rationalized violence compounds and conceals the real harm that must be addressed."
The writer goes on to emphasize that prisons are morally unacceptable, but also importantly the normalization of imprisoning humans to be morally unacceptable.