It has been fascinating to watch Jason question his lifestyle after seeing the way Michael has glamorized it since Claudia's death. Perhaps for the first time ever Jason has been forced to confront what he does for a living and is finding out what a profound affect his choices have had on those around him. It is ironic, although not surprising, that this sudden realization happened because of one of Carly's kids instead of his own. And while it would have been nice to see Jason make the decision to steer clear of mob violence for the sake of his son, I think it took Michael essentially holding up a mirror for him to see the full impact of this violence. Obviously if it weren't for Michael's personality shift Jason would not be questioning his duties as Sonny's enforcer at all. His decision to assume less violent duties within the organization actually has more to do with setting the right example for Michael, than regretting his own life choices. Regardless of whether Jason has gained insight into his own life through Michael actions, he seems to be the only adult willing to make any sort of sacrifice to save Michael. And while one would not immediately classify Jason's career move as a sacrifice, he is, in fact, risking his life because this could potentially be seen as a sign of weakness by rival organizations.
I must say that I found Carly's reaction to Jason's decision quite puzzling. She acted as though this somehow meant that Jason wouldn't be able to do as much for her kids once his duties changed. His violent lifestyle had nothing to do with how he helped her after Michael was born. He helped her in spite of that, not because of it. And while she certainly made a valid point when she stated that Michael would always be surrounded by violence whether Jason was a part of it or not, it should be noted that at least Jason is trying to help Michael. The same cannot be said for anyone else in his life. Out of everyone that is supposedly concerned about Michael's behavior, Jason is the only person willing to take any kind of action, whether it turns out to be effective or not. Sonny, in all of his stubborn naiveté, believes that he can will Michael to stay out of the mob, even while teaching him the inner workings of the organization. And Carly's life has been so consumed by Sonny and Jason for so long that she cannot see that her kids are growing up in an atypical environment that undoubtedly shapes their perspective on violence.