I think they drank the Macintosh kool-aid and expect you to have all your commonly used apps pinned. In Win11 this even looks sort of like a Mac dock. Still made no sense to ruin the usability of the start menu which they invented.
I read all the Windows 8 development blogs, and everything they wrote about seemed absolutely justified. Then you actually use the thing and it was a nightmare.
Same with their approach to hardware, the Duke Xbox controller tested really well, but then someone with daintier hands went to use it and uh actually its great for like 15% of the user base.