Whatever the reasoning behind the ribbon, I still associate the era the ribbon was introduced with 16:9 displays becoming common, starting with laptops. In that case, users would have had less vertical screen real-estate for developers to work with. If you remember the old Office, the menus were nested fairly deeply and it became a bit of a maze to use some of the features.
I had been using computers for so long at that point that I still don't feel 100% comfortable with the ribbon. It's fine, I can do what I need to do to work the programs. It's just a bit fiddly in a way the standard menus weren't. I used to be able to invoke commands with keystrokes and arrow keys. Now there's are bunch of icons on different scales, which sometimes hide if the window isn't maximized.