>>scyzor+(OP)
I do think work is important part to rehabilitation and also meaningful to pass time. Where I have an issue with is as you point out the for-profit nature of prisons. Even in Europe where one might not immediately consider prisons to be for-profit structures, one has inmates assembling ballpoint-pens or assembling low tech items for EUR 5,30 per day. This will ensure the inmate can purchase coffee and chocolates once a fortnight. But it doesn't change their employability after release. Once they get out it is either back to crime, or straight into another state facility (homeless shelter etc). This could be different if the inmate were actually able to save up some money while there. Sure an addict will likely sound it, or they might have a chance to put it into getting help.
There is another more meta aspect to it when considering a facility location. Many times the facility is a small town and then becomes the biggest local employer. Not just for guards but also lawyers, state attorneys, social-workers, judges etc. If that facility closes down it means these people would have to relocate. This is very hard to decouple and untangle.