The problem with MS is that their whole business has been about propping up either Windows or Office. Both are in jeopardy now and Microsoft is panicking, trying to save these products without the reference frame of what they really are, other than the two businesses that every other Microsoft enterprise is designed to uphold. Even the Xbox exists simply as a way to underscore the foothold of DirectX and keep Windows PCs the primary platform for 3D simulation.
Look at Windows 8. MS saw the tablet market explode and started to panic, aware that this may replace a lot of Windows PCs that would otherwise be sold to casual users. So they decided to integrate tablet stuff into Windows, so that Windows gets on devices that have this desirable form factor for casual users, and then they get the added bonus that the programs that work on their PCs will work just fine on their tablets and vice-versa.
This is actually a somewhat compelling proposition, the issue is that the implementation was horrific. Microsoft, in their attempt to continue universal dominance, failed to realize that people still on normal form factors, including the business market, would not take kindly to a full-screen, huge tile start menu, which is impossible to actually replace with something real, only a bunch of rough hacks to try and get back to a normal-type start menu. That's an interface for a casual device, not a serious business device, but MS has pushed it onto everything.
Microsoft needs to come to terms, and it can continue and adapt to market conditions. They may have to give up a little bit of ground in the short-term, but they at least won't stamp themselves out of existence. OS X is a consumer-centric OS. Android and iOS are consumer-centric OSes designed for entertainment and/or casual use devices. Windows is still the undisputed king in user-facing business systems. They should really not be revolting their business users by forcing them to learn certain mouse gestures in certain menus to find a shutdown option, or blanking out their screens with humongous, disruptive context switches every time someone wants to open a program. This is much, much worse than the iOSification of OS X that some have bemoaned, for instance; while there is an iOS-like menu, it hasn't replace Spotlight or Finder, and you can use your Mac without that intrusion if you choose. Even Apple recognizes that the interfaces are not directly and universally applicable to the different devices.
If MS recognizes that they need to focus on enterprise and conservatively integrate reasonable niceties from consumer-facing systems, they have a future. If not, they'll continue to flail about trying to be all things to all people, unwilling to accept that the tech landscape has changed and Windows may not be the universal thing anymore, and kill themselves.
Without such aggressive Metro integration, no one would have had any gripes with Windows 8. MS should quickly repent and issue Windows 9 with Metro as an optional extension and a classic explorer.exe shell as the default, because that's what business users need and expect.