My take - JB couldn't bring himself to walk away from the university he spent his whole life at. He always considered himself an employee of the school, not bigger than it, and it would always be up to the school to tell him it was time. The dude would coach until his body gave out if it was up to him.
Is he salty? Maybe. But none of us have ever devoted our entire life to one job, one place, one community so who are we to judge?
It'll fade. And over time, Jim will reflect, and he'll still be a big part of the university and the program that he built. We owe a lot to this man, and we should all be sad that he's no longer going to be manning the Syracuse sideline. Love you JAB! Go cuse, forever.