The Ribbon exposes features hidden in menus and sub-menus of sub-menus. How many people use Invert Selection? Probably a lot less then knew that there was an Invert Selection in the first place and now it's front and centre. Microsoft has done a ton of research and user pattern testing on the Fluent User Interface and Ribbon going back years.
Interface and UX design is not about designing around what people say they do, it's about designing for what they do do (haha do do).
I will purge examples from the MSDN blog but I have had the same arguments regarding my companies software when we moved to the Ribbon. We actually had a lot less push back then we thought we would.
I have spent a bunch of time defending the Ribbon against users who say you have taken away document space which is never true if designed correctly.
Shortcuts and for every option are always available and the Ribbon can support multiple shortcuts for the same commands.
While it appears that the Ribbon is the least customizable Window style its actually the most. A nicely formatted Quick Access Toolbar with collapsed Ribbon.
