IME there is a strong divide in opinions on the Ribbon interface. Almost all "everyday users" I know came down in favour after getting used to it. Most of the "power users" found it frustrating.

Given that the former group is much, much larger in practice, it's hard to blame Microsoft for making the switch, even if it does invite strong and vocal criticism from some people with legitimate gripes. I suppose this is the inevitable burden of designing some the most widely used business software on the planet.