Guess he realized Siri is an utter failure.
Theory time. And I don't know much of anything.
It seems to me, a company, no matter the industry, eventually, gets to the size that it cannot sustain the vision, scope, and purpose of its institution. If it's a good company, it's an idea. Siri was and still is, a very good technology. But there comes a point when the original idea havers cannot sustain development. They need more members. Sometimes it will happen, the potion arises in which the original idea havers will have the opportunity to join a group of idea havers much larger than themselves.
What is the outcome of this? You can only have a certain idea of what the culture of this new group of idea havers is really going to be like. Some people can deal with these cultural changes better than others for so much time. The people who develop software are smart. Especially if one gets to the level of a company like Apple, you're really smart. But smart people are also very independent. And being pushed around by a lot of, ultimately, cultural barriers, some really smart people can only take it for so long. And so they leave.
Eventually, a company can only find a certain amount of people who are really smart, who can also put up with, or love the culture. Maybe Apple is nearing that tipping point.
Another thing that can break down a company is a management change.
I don't know if anyone noticed, but there has been a veritable flood of departures
eherm, in the last year... What is keeping I've there I wonder? He was Jobs self proclaimed corporate soul mate. The love of design I suppose? Or maybe he is just one of the few who can put up with the culture of Apple. After all, he was hired in '92. Five years before Jobs' return and seven after his first departure. Right on the brink of Apple's downward spiral...
I honestly don't think anyone intended on him staying longer than needed. It was probably already discussed that he would stay for the transition period only.
Or this.