I’d argue that it makes plenty of sense when you see it through the lens of terrible people profiting from human misery wanting to hold onto those profits: letting prisoners learn useful skills leads to lower recidivism which means fewer dollars going to the prison industry in the future. Meanwhile more racist books in the library means less hassle to prison guards when the prisoners turn on each other, boosting gangs that alighn on racial lines, instead of pushing back on the assholes actually making their lives worse.