Seems pretty serious and probably very real KPI. We live in a capitalist society, after all.

Why does the parent get downvoted?

Because the majority of prisons are not private and all the perverse "muh headcount, muh resources, muh silo" incentives that you see in government are more applicable.

But the private prisons have lobbyists trying to shape legislation. I doubt the state-ran prisons have similar sway.