I was mostly joking when I wrote that.
But, you raise an interesting question... how much value is there to the local prison behavior in the ability to earn a little discretionary income for treats? Does it help in rehabilitation? Or do most prisoners have access to outside funds from gang or family?
I was pretty sure your post was tongue in cheek, but in my mind, I could hear prison reform activists chanting it and wondered just how much they would think was enough? ;)