For over a year now, I've struggled to understand Windows 8 (and Windows RT) and to effectively communicate the many changes that Microsoft has added to this release. What I've arrived at is that Windows 8 is nothing less than a new mobile platform that happens to bring along compatibility with current-generation desktop applications, and that Windows RT is the purer version of this future vision, with less backward compatibility but more mobile-oriented aspirations. And that's all fine. But the big question is … why? Why did Microsoft throw a grenade into the middle of Windows and institute the biggest-ever change in this platform?