The "mostly successful efforts" you speak of seem to have been focused on delivering ads, TOS-backed spyware and those weird Metro apps. The result is certainly simpler from a strictly visual standpoint, but more usable is something that I wouldn't be too willing to concede without some data (and I don't mean install data/user base, given how Microsoft's customers don't have much of a choice in this department). Frankly, I don't see how the weird start menu or having both the Control Panel and some weird Settings thing help with usability, but UX is a surprising field, I guess.