In case you thought otherwise, I meant WinRT as in Modern apps, not as in the ARM OS.
If you are talking about Windows 8 (Intel), then you seem to be claiming that Microsoft has purposely chosen to target one OS at two different audiences, the desktop audience and the tablet audience, with no intention to bring them together for a cohesive user experience.
That's exactly what I'm saying. Windows8 Metro apps are not aimed at content creators, and according to most of the people I've met at MS, is explicitly not designed to remove desktop applications from the equation.
Metro apps are just a new way of doing things for the post-app world we live in. Users want to be able to download crappy apps without fear of pwnage and to be able to use them in a swishy way with centralized ownership, content controls and design cohesiveness; to put it another way, people do actually want iPhone/Android apps on a PC, and that's what Metro apps give them.
But Microsoft isn't stupid. They fully realize that some applications are never a good fit for that model. Visual Studio (which is used by at least 50% of the employees of Microsoft) is a clear example of an app that would never really fit into Metro. Microsoft also realize that their entire business is founded on binary compatibility with older versions of the OS. That's why most applications just work on Windows8 despite having been written and compiled on machines before Windows8 even existed.
Perhaps it's not obvious to people who've never been to Redmond and seen the work they put into app-compat, but the simple fact of life is that the desktop isn't going away, and it never was going to. Metro might be front-and-centre in the adverts and in the mind of content-consumers (which let's face it, is most home users), but to content-creators, the Desktop is still critical, and will continue to remain and evolve with Windows for the foreseeable future.