But prisoners time has to be managed both to enable everyone to get through the days safely and to provide an element of routine and control; they can't spend all of it sewing mailbags or cultivating the prison garden, or doing OU law degrees.
And have you tried to find something to watch on TV these days? Wall to wall reality TV would finish me off. Maybe they don't have it as good as people think.
Also if you do make peoples lives harder they will probably just get used to that as the norm.

In all seriousness, taking away someones liberty and choice is already a huge deprivation, is it not, ie away from family , friends, children?