> The development costs for Windows (as a common platform, stripped of any add-on that could be provided by other competitive players) are a footnote in the costs of the global software market for Windows. There is indeed a complex problem to be solved of how to organize an open platform so that the development costs are paid, but it's not fundamentally a question of resources. Multiple companies and open source teams have achieved roughly similar feats with many orders of magnitude less resources than what MS rent-extracted from the Windows OS consumers.
I was talking about Windows Phone, a mobile operating system. To have an open platform, you have to have one big company paying and managing its development. Otherwise you end up with fragmentation, lack of ABI stability, backwards incompatibilities and "distros" like with Linux on the desktop, and that is not exactly a consumer success.
If you want an open platform, you have Android. But apart Huawei (which was forced by US government) and maybe some few small manufacturers from China, I don't see much competition in the space.
Contrast this with a parallel world in which we have Android, iOS, Windows Phone, WebOS, Bada, Tizen, Maemo, BlackBerry etc.