> Because it creates perverse incentive for government to put more people in prison.
Except for some rare cases, I think you'll find that the cost of keeping an inmate in prison for a day makes it that you never break even
Breaking even is more attractive than debt for a cash-strapped city
Or the taxpayers foot the bill for keeping the inmate in prison while private interests (including but not limited to private prisons and select contractors) take additional profit off the unpaid labor instead of passing savings to the consumer