It's not complicated, it's right where it should be, it just has a label that somehow manages to be both highly correct in a technical sense and completely unintuitive to anyone who doesn't already know what it's called.
It's not only that, but also the way the ribbon UI resizes when things don't fit on screen all at once. You never know, if there are functionality that's missing from view.
YES - The ribbon UI has been around for ... what, decades, now. And it's still less usable that regular menus :(