Blender works better on Linux? That’s nice. But lot of the professional art tools don’t work on Linux at all. And gamedev artists rarely prefer to use Blender or Gimp 
Unreal support for Linux doesn’t matter too much because entire industry is avoiding this platform. It’s 2017 and even video drivers don’t work properly.
You distort reality so it could match your point of view 
TV sales are also falling for the first time in history. It because people don’t feel a need to replace current PC or TV.
It doesn’t help desktop Linux in any way. To be honest I don’ know what could help this system to be more popular for personal use. Maybe world doesn’t need it? We already have few great systems satisfying various needs.
BTW, Microsoft makes most of it money on software. Declining hardware sales? Not a big problem, as long as folks keep using MS services.
https://www.microsoft.com/investor/reports/ar16/index.html
Of course Windows Phone is total failure. But it doesn’t matter in this discussion. Linux mutated in form of Android has a good life, right? 