It's a good ol' fashion power play for who will run the company after Iger's gone. Much of what's being leaked is spin; justification after the fact for what's transpired.
Some are suggesting Staggs is being pushed out the door. The reality is that he's still has a contract and cannot be forced to leave. He needed to show more fortitude in the face of adversity. Getting the top job is a cutthroat business; Iger had to battle and put up with a lot of grief before becaming CEO. Staggs should have expected no less of a fight.
Staggs had at least another year to turn the tables. The fact that he's leaving now suggests that, current profits aside, all is not well in behind the curtains.