I don't know why some writers insist on making it a direct competition between different ARM platforms. Nobody in the regular PC marketplace decides before their computer purchase which chipset they will purchase then decide which operating system makes the most sense based on that. They chose their OS platform based on their software needs, then they look at hardware. And if their software needs can be handled by any OS, then overall price, performance and capabilities become the next factors, no one marries themselves to ARM or Intel before taking those factors into consideration. So, ARM on Windows is not in direct competition with ARM on OS X or Android, it is in direct competition with Intel on Windows.