The truth is that prison is a place where emotion is suppressed to a high degree. Emotion is viewed as a weakness, a vulnerability, and is therefore discouraged and conditioned out of the people there. That being said, many in there, who have decided to rehabilitate and change their lives for the better, make an effort to reconnect to their emotional selves. It is a long process and there are many groups that help them to do that.
But it is very difficult to reach the MAJORITY in this way. The MAJORITY will appreciate a rational, logical, and less-emotional approach. They appreciate an approach to their reason. This is what they are comfortable with.
Stoicism does not rule out an emotional experience, but it certainly puts reason first, at least in my limited observation. This is PERFECT for the folks inside because Stoic concepts and principles already align with their ways of being. If I had discovered Stoicism in my early years of rehabilitating myself, I would have taken to it like a fish in water. It would have been my guidance as I also worked on reconnecting with my emotions.
Stoicism is a vital side of the holistic approach needed in rehabilitative programming. More than that, it will be something quickly beneficial to the people, as opposed to something uncomfortable they have to wade into. This is not to say that living a Stoic way of life is easy. Not at all. But it will be EASIER to digest.