rcgs is referring to the way that Microsoft has, over time, added more and more buttons into the ribbon, so that at present most Microsoft applications have almost all their functionality accessible through the ribbon. rcgs would argue that this defeats the point of the ribbon in the first place (I'm inclined to agree).
The ribbon is not designed to be an edited toolbar with a single row of just 10-20 functions. It's a wholesale replacement for application menus. Every new function and feature should have a placement on the ribbon, or else how would you otherwise activate it?
Organization of the ribbon is important, though, and it may take some time to learn where stuff is, or how it's organized. The first time I used it with Excel, I couldn't find the Pivot Table button. I thought it might be under [Data], but you're [Insert]ing a pivot table instead.