One, Correlation vs Causation? Another article I recently read stated that PC sales, as a whole are down. Why? Because computers built in the last 5 years are plenty powerful for most home users. My 4+ year old, quad core i7 with 8Gb of RAM and 2TB of disk space is alive and well, and fully capable of doing everything I could ever want it to do. Not to mention tablets hitting mainstream (http://newsstream.blogs.cnn.com/2013/04/12/pc-sales-down-but-not-out/)
Because of this, I have no need to build a new system, and no need to buy a new OS. OS sales are largely dependent on OEM sales.
Two, every 2nd Windows OS sucks... That is how it has always been. It seems Microsoft does something different and it takes two generations before people accept it.
-Windows 3.1, Awesome
-Windows 95 - Blah
-Windows 98 - Awesome (Compared to the previous two)
-Windows ME - Set it on fire!
-Windows XP - Awesome
-Windows Vista - Blah
-Windows 7 - Awesome (When compared to every other version)
-Windows 8 - WTF?
-Windows ??? - Profit?
Windows is far from dead. Microsoft tried something new, like they did with the Ribbon in Office for Office 2007 - people HATED it. Now, I couldn't imagine using Office without the Ribbon. People hate change.