The new Ribbon is basically a menu that is built out of extendable XML parts that can grow and shrink on context.
I don't see why its bad at all frankly. It is most definitely a win from a user-experience perspective. Even more so... its a win from a developer perspective.
A single XML file can serve as a consistent menu across old-style C++ COM programs or even be used in the new .NET / C# programs. You no longer have to worry about resizing icons to the user's screen, Ribbons automatically stretch or shrink as necessary.
Just from an API perspective, they are far more powerful and consistent way to communicate between the user and the program.
--------------
Menus of old can be well designed, but they won't be consistently designed across all programs.
That said, the older menu system of MS Word was well designed. The real issue was that they totally reorganized everything in a feeble attempt to get people to start using the more advanced style options of MS Word.
"Properly" using MS Word involves using it more like LaTeX or HTML: you use semantic markup, and then later style your document. (or use a style that is consistent with the rest of your office).
But people would rather just hit the bold button or italics button. They don't want automatically generated table of contents or figure charts... they want to manually type that stuff in... like a typewritter from the 80s or something.
I don't know, I can agree that the new Ribbon interface makes it harder to do certain things in Word, but that was unfortunately the purpose. People need to learn the semantic-markup style of Word and start using better methodologies to organize their Word Documents. But no one seems to put in the time or effort to learn how to use the programs they use every day.
Anyway, I've put in the effort to learn the "new way" Microsoft wants you to use MS Word. And I personally agree with Microsoft, documents are much more consistent, and much easier to update styles consistently across the whole document when you focus on styles first and foremost. Hiding the Bold and Italics buttons (and several other popular... but "wrong" features) was a wakeup call indeed.
The problem is that most users don't like being told that "they're using the program wrong". Part of it is truth (really, the new way is better). Part of it is business based though (Using a document editor as a fancy typewritter means you're ignoring a lot of useful features... and are probably better off using the much simpler Google Docs, or OSS like Abiword)