I appreciate what the article is trying to say and I more or less agree with it but the arguments supplied and the writing was not worth the length of the article.
Tl; Dr: "Oppressive systems harm everyone, including those they claim to protect — and South Africa proves it."
Especially in the US, I think it's easy enough to see that mass incarceration does actually harm the entire society as a whole and therefore those that it claims to protect including the rich. So regardless of what it's claiming to be able to do, the justice system in the US is intended to be all in support of "line goes up". I wonder how easy it would be to prove that, in fact, it does not do this and in fact hurts the interests of those whom the penal system is designed to protect.