It's a matter of opinion about whether the changes are good or not. Opinions aren't right or wrong. However, the claim that 10 was not designed solely around being the best desktop OS it can be is not in dispute. You may disagree whether that goal was reached with XP, Vista, 7, or any version of MacOS for that matter... but they were all designed only for the desktop.
Windows 8 and 10 are compromises between two things that don't really need to go together. Each is (at best) a jack of all trades. At worst, 10 is an advertising platform meant to get us to buy other stuff (especially Windows mobile devices) first and a desktop OS second.
Perhaps-- but it's not available to me yet, so I can't judge it. I know that 10240 doesn't even crack my top 5.
I would put XP on top, 2k second, 7 third, Vista 4th, 9x fifth... with the understanding that each is evaluated in its own time, not by current standards. 9x is not usable by current standards, of course. I've never used any other versions since 9x, so I can't judge them one way or another.
Isn't the topic of this thread about how the entire control panel is going to be in a Metro app? What are we supposed to do-- never change the settings? If it were as simple as not using Metro, a lot of the contempt for 10 would be alleviated. Even that, though, would not fully solve it. We'd also have to back out all of the design compromises to accommodate metro (elimination of the Classic/basic themes, elimination of Aero glass, making everything flat and stark and white), that would be even better. Maybe the latest insider builds will make some progress with that; I am hopeful about this.
The analogy someone else made about Windows 10 detractors coming here to post being like AMD users posting at an Nvidia site is not accurate. AMD and Nvidia are competitors; each would prefer that everyone never use the other's product. 7 and 10, though, are supposed to be different versions of the same thing, and the maker of 7 doesn't even sell it anymore, and is very aggressive in trying to push 7 and 8 users to 10. We'd love to have the option of never using the "other" product-- but there is a definite end date for 7 and 8, and we've been told that 10 is the last Windows there will be. There's no definite point beyond which AMD users will be forced to change to Nvidia (other than AMD going belly up, which I hope does not happen).