Comment 6 for bug 328679

I think that the gnome-compatibility plug-in should be considered a default-on whenever compiz is enabled by Ubuntu GUIs (such as the System/Preferences/Appearance dialog).

If you use Appearance to turn on Compiz, on a new install, not only will keyboard shortcuts break instantly because gnome-compatibility-plugin isn't activate by default, but you'll also have no easy way to fix this (well, apart from turning off compiz again) because the compiz settings manager is also not installed by default on a new Ubuntu installation.

I don't think many new users will make the connection between turning on graphical effects and their key bindings breaking. And although you might then argue that new users won't be using Alt-F2, they probably will use printscreen.