Windows 8.1 will most likely be my last version of Windows that I run. For me, it comes down to who does the computer belong to - me, or the company that makes the software the computer runs on. Microsoft (and many others) clearly believe that once you put their software on it, your computer and what you do with it belongs to them. The amount of 'telemetry' being sent back to the mother ship and the forced updates are my primary factors to moving away from Windows. In fact, the primary reason this computer still has Windows is due to Sonar/Cakewalk. I have switched over to Linux for just about everything else.
I should also note that when Windows first appeared, I was a very big proponent of the software and the company. But as is typical, as the company got bigger things changed and not necessarily for the better. As they changed, so did I.
So yes, my next computer will be upgraded, but not with Windows 10.