>I don't think it's so much worse to have the window decorations being "off" when the whole application looks wrong in your DE anyway.
I do. When an application merely "looks wrong", that's fine, although if the decorations were all in the wrong place and inconsistent with everything else, that'd be very irritating, and from the user's perspective, an awful regression.
But when applications provide no "quit" functionality or shortcut (I've seen many that are like this, assuming the WM will take care of them), or they lock up, then my window manager will save me. I've got a tiling manager where I can right-click on the title bar, click "Kill", and it will send SIGKILL to the application. (There is also a keybinding for SIGTERM, but I can never remember what it is.)
The bigger issue, IMHO, is still the lack of tiling window managers. I have no interest in manually resizing and moving windows, especially when it's up to the application to provide me a sane way to do it.