That and MS implementation is a cardinal sin of UI design - don't hide/move widgets willy-nilly on the user.
With a menu, I was always told to gray out options that were inapplicable. Everytime I use the ribbon, it seems as if I have to hunt and peck through the tabs till I find the option I want again.
Now you could have different modes of operation that show certain widgets. But the user should then switch mode explicitly, not have it happen when he does something on the doc rather than on the ribbon/commands real estate.
All of this whining would be moot if MS was a bit more willing to allow users to decide how they want to use the system - there are utilities to show menus, so allowing users to switch between menus and ribbons would solve all this. Even a degraded menu mode, where real power use would require dropping back to the ribbon would be an acceptable compromise.
But of course, this is the company that justifies Telemetry as about enhancing the user experience.
Biting the hand that feeds IT
