It's not just the Haredim who have to improve

And not go to jail at all.

These guys don't give a damn about Kosher. They want their own cuisine. Cooking especially for a dozen or two would render the food more edible than having to eat what the hundreds eat.

or are put into jail/prison for what should be civil offense fines. A fisherman was sent to prison for eight years for using the wrong kind of fishing nets, for example. One former US Congressman who went to prison after being framed said he estimates there are 270,000 prisoners in US prisons who were framed. The ones who were not framed are often given ridiculously long prison sentences. Rabbi Yahoshua said to visit HaShem in the prison, so many people in prison even 2,000 years ago were in HaShem's camp and thus were worthy to be visited although that was illegal back then even to visit a relative condemned by the INjustice system of Rome. Back then, the name of criminals could not be mentioned even in conversations or those saying the names of criminals would be prosecuted for breaking the law! Isn't it a kindness to provide Kosher meals to those who are wrongly imprisoned? That happened even to Yosef the Patriarch.

That should be the norm. All these prisoners find religion in order to disrupt routines and call attention to themselves. How religious were they when they committed the crimes that got them to prison in the first place? Isn't crime against the Torah?