Jason has made it clear that he is going to Nationals for the sake of Nationals. He has said that, this time, his goal at Nationals is not to make the World team. (He did say, though, that he would be happy to go to Worlds if he was selected for the team, but that is not the reason he is doing Nationals. He didn't like the idea of ending his career at the Olympics without his family there, and last year's Nationals was really crazy and weird.)
I think that the skaters have to decide what is best for them physically and mentally. (And, for some of them, finances enter into it. Skating is an expensive sport.) Jason understandably felt he needed a break from competition after a long career and a very crazy and exhausting Olympic season. I actually really respect the decisions he is making to focus on his health and happiness.