To add a small amount of balance here, I've switched to Windows 10 and it's fine. For background - I'm notorious for not upgrading at work. My main desktop PC is Windows XP and my reaction to the news that Microsoft had dropped support for it was "thank god, no more updates". On my laptop I've got Windows 7 and really like it. So, when I came to buy myself a brand new gaming PC recently (mostly for Elite) I was faced with this question - Windows 10 or Windows 7. I did a fair amount of research and came to the conclusion that Windows 10 was a lot better than Windows 8 (which I hate) and frankly I should just bite the bullet. I want my PC to last a fair while (and ultimately to support the latest VR developments) and I figured that, over the next few years, there's gonna be more and more support for Windows 10 and less and less for Windows 7 so I might as well get used to it now rather than have to change the OS on my machine further down the line. While I agree that the look of Windows 10 is pretty uninspiring I've had no real issues with it plus I get the sense that it's generally a more efficient operating system than 7 or 8.
Oh, and I don't really give two hoots about all the Windows 10 big brother spy paranoia plus it's very easy to turn off those data sharing features (which I did for performance reasons - I don't want my PC wasting any valuable bandwidth).
So, a thumbs up for Windows 10 here.