You can like the UI for something that is a usability nightmare. How is that silly?
Windows 10 works like older versions of Windows because it looks like old versions of Windows.
Really? I don't see any old Windows UI designs on Windows 10....oh....you were talking about design patterns. That is not the same thing as the final UI design. The UI design takes into account design patterns (which is more UX), things like color, font size, icons, etc. which I think is Matias Duarte was talking about.
UX is UI, but UI is not UX. Good UX governs all that is contained within it, each discipline within solving for a particular aspect of the user experience. The very nature of UX is segmented problems that get solved, then combined to form a greater whole. (Google the 5 Planes of User Experience)
I'm afraid I don't see how that can happen in one fell swoop, as you seem suggest.