Yes, Microsoft's position is understandable, but I still do not think it is a smart move from them. At this moment, Win32 is still the biggest competitive advantage Microsoft's Windows has over any other OS. Microsoft is victim of its own success. Yes, Win32 is old, it is sometimes painful to use, but it gets the job done and there are countless developers knowing how to create Win32 applications.
Microsoft feels they are slipping behind, because the API of other OSes look so much more modern. They are desperately trying to create a new platform/API to replace Win32. The .net experiment did not succeed, it is now 10 years since it was introduced and there is still no .net-only OS for .net apps. Almost every larger .net desktop application is PInvoking something and would not work in a Win32-free environment...
And now, Microsoft gives the new API/platform another shot with WinRT. While I applaud them they do not want to force a garbage collector on everyone anymore, and WinRT may be a good API, I do not believe they have a good position and marketing power to push it through this way. Developers would have to learn a new API in order to be able to write applications for ARM Windows 8 tablets. If I want to learn a new API, why not make something for Android instead? The Windows brand is strong, but without Win32 backing it up, it may not be enough.