It's fine to be critical of his coaching, but that doesn't make Cosgrove a bad person. He could be a great guy for all I know, and I sure don't have any ill will toward him. People that personalize this or don't care need to get a grip (maybe counseling would help). I wish him and his family the best.
My sister developed leukemia (chronic myelogenous) and some new wonder drug put it into remission inside of 6 months. There are lots of different kinds of leukemia and some can be treated effectively. Hopefull this turns out well for them.