We have, but the system that the article is critiquing is, in fact, the one we presently live under.

You can, in fact, punish people without prisons. You said it yourself, we've done it with other means in the past. The article addresses incarceration specifically.

The whole article intends to convince us that incarceration should not be punitive, but restorative.

You directly missed my point. The carceral threat is only one stick, and judging by recidivism data, not one that is working particularly well. Perhaps we should examine another set of sticks, or even maybe, perhaps consider another set of carrots. Dismantling the prison industrial complex will not itself create predators, which is the claim I responded to.