Because it creates perverse incentive for government to put more people in prison.
Right now the punishment is confinement. When you add effectively unpaid labour in prison as part of acceptable punishment, you're also paving the way for a future where unpaid labor as a standalone punishment is also acceptable. That's just slavery by law.
Right now the punishment is confinement. When you add effectively unpaid labour in prison as part of acceptable punishment, you're also paving the way for a future where unpaid labor as a standalone punishment is also acceptable. That's just slavery by law.