> used to fill entire factories with labor for private benefit, while taxpayers foot the bill and prisoners work without fair wage.

How would taxpayers foot the bill if the prisoner's wage is used to finance his stay? At worst, it would lessen the cost of his stay.

> You're turning this into a prisoner

You turned it into a prisoner's rights issue by claiming that forcing a criminal to do some actual work (like every taxpayer does) amounts to slavery. Your opposition to letting criminals work is therefore due to moral and not practical considerations.