Maybe, but two things:
1. I don't know that we have a better replacement
2. He was actually doing well the last couple months. Since June 1, he had a 2.82 ERA, was striking out 8 hitters per 9, and had greatly reduced his walks.
Then another team should be happy to pick him up.
When you leave a game angry, throwing fits and shooting looks into the dugout when you are up by 20+ freaking runs... you are telling everyone in the organization who is your #1 concern.
If we are gonna make our run, limiting selfishness is a good thing.