On consoles. On PC that game runs very very well. So if you detach the game from it's console version I'd say it deserves the 10, if you don't detach the game and rank specifically how it runs on the consoles than yes you'd be right. It should have had two separate reviews so that people would have had a clearer idea as to what to expect as I KNOW i'd have been disappointed with the performance on consoles had that been my only option, but again it ran real well on PC. Aside from a few random crashes I played that game start to finish at 60 fps the entire time without any issues.
on PC the game still has horrible combat, but whatever most people don't seem to care about gameplay these days.
Witcher 3 is like the 2015 version of GTA IV for me. I don't get how such a mediocre game is receiving such praise.