Well the only public facing RadEditor is this one in the forums...right? So in that case I can see your point. However it's primarily used literally everywhere in the backend, and I'd like to see anyone whos happy with it. Undo barely works, and if you get caught in borked content hell (like it nests a <h2> in a list or something) unless the user knows html to jump into that mode...you might as well just start from scratch.
Remember this classic post?: http://www.sitefinity.com/developer-network/forums/general-discussions-/radeditor-has-issues-when-i
I'm not knocking the engineering marvel OF the radeditor, I can't even fathom how complex it is to work with and maintain cross-browser...but I think it's now become TOO complex where it's borking more than it's helping.