Clutter

Er... if you never see the screen background because you have windows open all the time with work in them, why do you care what's painted on the background? KDE 3's kicker put useless stuff on the desktop background, too (removable drives, often quite out of sync with the *actual* set of removable drives on that machine), but I didn't give a damn because I never saw them.

(KDE 4, now, has made my desktop useful again. I have an empty virtual desktop specifically so my plasmoids are visible somewhere.)