I think they did really drop the ball not having user customisation in there from day one thou.
The 'legitimate' complaints, such as not having the Union/Intersection buttons in Visio in a sane place (developer?!) are easily fixed by this.
A lot of the other one is just band wagon jumping, I bet if MS had kept it until 2010, when everyone was having a Windows 7 love fest in the press, they would have had better feedback.
Those who really use office for a huge amount of the time that I've worked with all like the ribbon, mostly kept in closed mode, acting just like an enhanced menu, the only toolbar needed is the contextual popup one. However I can't fathom why they didn't overhaul the dialogues too.
What someone might find odd thou, given what I've just written, I'm ripping a ribbon out of an App I've taken over for a client, its just not an appropriate UI. I'll be copying Opera's one a bit, tabs in title bar, with indicators on the Tab, then the toolbar at the top.
If the users don't like it in UAT, well I'm planning on being some 3,000+ miles away, that would be a BA issue.