I have the same gripe for pretty much everything that MS has done since WinXP. They decide what's the best thing to put on your menus for you instead of letting you do it yourself. I always disable "personalized menus" (which really is a misnomer) in windows and in office and everything else.
Personalized menus isn't as prevalent as you seem to be making it out. Yes, I hated it in Office, but it was easy to turn off and wasn't in the product for long. Where else have you seen it?
And really, it wasn't MS deciding for you. The idea of personalized menus was that you would only see the items you use most often, so there wasn't as much clutter in the menus. It's one of those things that's not for us, it's for the normal people who use 2-5% of what Word can do.
But yes, I turned off personalized menus whenever I saw it.
Things appear and disappear even if you just resize the window.
I can't speak to the context change you were talking about, but I'm curious what you think should happen when the window is resized. What else can they do? Yes, it changes, but it kind of has to. And the way it changes is that it just compacts it more. As you narrow the window, it first truncates that annoying Styles section (by showing fewer styles), then it removes text from icons, then it compresses two rows of icons to three*, and then it starts hiding icons behind drop-down menus.
I don't mean to come off as an MS apologist, I just want to make sure we give them crap for the right things

*this implies that they could have everything more compressed to begin with, and address Andy's vertical screen space issue, but that might look too confusing for the normals
