You're partly right; prisons aren't meant to be fun or enjoyable. What they're supposed to be is reformatory, but these days, they're just for warehousing human beings. With budgets for reform being deflected toward building bigger and better mega-prisons (the Supermax) the focus now is keeping them alive until their release (if ever), not rehabilitation or reform.
http://en.wikipedia.org/wiki/List_of_miscarriage_of_justice_...
You're partly right; prisons aren't meant to be fun or enjoyable. What they're supposed to be is reformatory, but these days, they're just for warehousing human beings. With budgets for reform being deflected toward building bigger and better mega-prisons (the Supermax) the focus now is keeping them alive until their release (if ever), not rehabilitation or reform.