I think if Jayson Werth was the kind of intuitive, team-first baseball player that Jayson Werth seems to think he is, then at some point in the past two seasons Jayson Werth would have had a quiet sit-down with Dusty and transitioned to the bench.
The absolute final straw was him not sitting down in the playoffs for the betterment of the team, still thinking he's a playoff hero or something. I have no hard feelings towards him - I wouldn't mind seeing him come back sometime soon as a coach. But he is clearly delusional about his current playing abilities, as most old ballplayers are.