To me, this is not a surprise at all. Privately I mentioned to others close to Skype and Microrosft well in advance of the appointment of any inside candidate to the role of CEO at Microsoft would cause an immediate departure of others on the senior leadership team. So far two have left following the appointment of new CEO Satya Nadella.
I also said privately that Bates would not be the pick and he would leave. A couple of reasons why:
1. He's a consumer guy at this poing, and while MSFT needs someone who clearly understands consumer marketing, he's not going to win the job, even if he was the best candidate from the insiders.
2. He's too much a Silicon Valley guy. No matter how you slice it, MSFT wants people who are fixtures in the Seattle/Redmond tech scene more.
3. Outsiders in key positions never fare well at MSFT
4. Acqui-hires into MSFT are not part of the MSFT culture.
For Bates the departure is a good thing. It's still early in 2014. He doesn't need the job, as his exit from Skype was lucrative. He's a proven executive who can go pretty much anywhere he wants. While some may mention soon to IPO GoPro as a great place to consider, he could also easily end up at a VC firm as an EIR, or even FaceBook as CEO.