No one was more public as the face of Windows 8 than Microsoft exec Steven Sinofsky. As Windows Division President, his sudden departure from the company only two weeks after the Windows 8 launch turned heads across the world of technology. It’s easy to always view the departure of a long-time, key executive as a loss, and speculate on how the company will fill their shoes, but in this case Microsoft may have done itself a big favor. Even though Microsoft and Sinofsky are both working hard to make his leaving the company appear to be part of an organized transition, the poor timing, total lack of a plausible back story, and insider reports of an impromptu meltdown and summary dismissal add up to a more likely scenario that Microsoft CEO Steve Ballmer had had enough. Now, our own sources tell us that the sudden dismissal — enacted by Steve Ballmer himself — was a surprise to both Sinofsky and his staff, but there is no shortage of speculation as to the reasons.

Whether it was a decade of Sinofsky’s foot-dragging when it came to tablets and touch-based interfaces, or the poor reception of the software on Microsoft’s flagship Surface RT tablet may never be known, but Sinofsky’s dismissal appears to have come about very suddenly. Clearly Ballmer will assume a more direct role in Windows management, with Windows VPs Julie Larson-Green and Tami Reller now reporting directly to him. Larson-Green is best known as a driving force behind the new Windows 8 UI and, prior to that, the Office ribbon bar. Reller, who is less well known, is a well-respected executive who came to Microsoft in its acquisition of Great Plains.

Sinofsky was not a team player

Since before the Windows 8 launch, we’ve been told that Sinofsky is smart and driven, but also exceeding hard to work alongside. Former members of the executive staff describe Sinofsky as “the most difficult and arrogant person they have ever tried to work with”, and as being “toxic to teamwork.” One anecdote reported by the New York Times, and confirmed by our Microsoft sources, says a lot about what he thought of himself and his peers. At a management offsite earlier this year, instead of making a scheduled presentation to the rest of Microsoft’s executive team on the progress of Windows 8, Sinofsky apparently told them to read the product blog, answered questions, and then left the retreat altogether. It’s hard to imagine mercurial Steve Ballmer putting up with that type of behavior in anyone — let alone a senior executive. Not wanting to rock the Windows 8 apple cart before launch is just about the only thing imaginable that would have kept Ballmer’s temper in check at that point.

Ballmer had been frustrated by Sinofsky before. Microsoft partners apparently had a reference design for tablet hardware ready in time for Windows 7. Sources tell us that Sinofsky refused to add support for it in Windows 7. Whether it would have been successful is hard to gauge, but it would have put Microsoft in the tablet market several years earlier, and possibly around the same time as Apple’s original iPad. However Sinofsky, to his credit, was in the middle of doing a yeoman’s job of turning the Windows ship around after the Vista release.

The Windows 7 stonewall wasn’t the first time Sinofsky had worked to crush a Microsoft tablet project. He is widely assigned responsibility by those involved for killing the Courier tablet project and helping drive the project’s leaders, Robbie Bach and J Allard, out of the company. As head of Microsoft’s Office division at the time, Sinofsky’s foot-dragging and de-emphasizing of pen and touch support in Office is blamed by ex-Microsoft employees we spoke with for the poor reception of Microsoft’s convertible laptops. Even so, Sinofsky doesn’t deserve all the blame for Microsoft’s slow progress in tablet computing. Other Microsoft veterans involved in the efforts, who spoke with us confidentially, blame the lack of focused product visionaries at the highest levels of the company.

Sinofsky’s run-ins weren’t limited to tablet computing initiatives. The Wall Street Journal’s well-connected Kara Swisher even links him to the departure of Stephen Elop for Nokia. With Sinofsky’s aggressive attitude towards his peers, it is not hard to imagine some fireworks when the modern, touch-centric Metro UI from Joe Belfiore’s Windows Phone group was destined to become the new Start screen for Windows 8. Whether Sinofsky’s traditional stubbornness helped cause the customer-unfriendly decision to dump the Start button or not is unknown, but it certainly isn’t a surprise that Metro and the desktop don’t play nicely with each other. Since Larson-Green is reported to have been one of the key drivers behind the Metro UI design, it may be optimistic to hope for the Start menu to reappear anytime soon.

Did Microsoft lose a leader or an anchor?

There has been a lot of speculation about whether Microsoft took a risk by dismissing a key product executive during its largest ever Windows transition. Much of that speculation centers on who will provide the vision for Microsoft’s future. Those speculators are asking the wrong question though. From those I’ve talked to who have worked with him, Sinofsky was the guy who could “make the trains run on time,” but “didn’t have an ounce of strategic vision.” Perhaps that is an extreme characterization of Sinofsky, but a decade-long track record of pushing company visionaries towards leaving tends to reinforce it.

If Sinofsky was actually part of what has been holding back the evolution of first Microsoft Office and now Microsoft Windows, then the right question might be what kind of exciting new and visionary products will we see from an executive team that doesn’t have to fight with him for every step of progress?

Now read: Windows 8: The disastrous result of Microsoft’s gutless equivocation