Right now we have the multitudes running a conglomerate combination of Windows XP, Windows Vista, Windows 7, Windows 8.1 - I imagine all of these operating system, and remember when we had a single MS OS shared among all people business and personal alike. Part of the appeal of XP was that you could depend on finding it anywhere and everywhere and nearly exclusively. Microsoft has too much out there - and this includes their server offerings - and I strongly suspect MS is working toward that lost, uniform ubiquity that they had with Windows XP.
Again, I'm a long time MS basher, but I think giving them a post-Ballmer chance is fully in order. I expect a lot of them over the next few short years, and that includes a single OS to rule them all..