Less than 9% of prisoners are in private prisons, so I don't think that would make a significant difference. I mean it might be a good thing to do, but won't help the vast majority of prisoners.
The "food" providers, communication "providers", the companies paying virtually nothing for labor, etc. The folks focusing on the raw percentage of prisoners forced to stay in private prisons are missing the forest for the trees.
Sure, but the grandparent was talking about how it's not uncommon to have no TV, bad food, etc. in prison. Given that private prisons are uncommon, clearly privatization isn't the main cause of these problems.