I don’t really see the contradiction.

How much of the eye-candy (IM, etc.) is so woven into the desktop that it's impossible to remove?

With OS X and Windows, I add the extraneous stuff - it doesn't come pre-installed and pre-enabled.

I'll stick w/XFCE, thanks. It's based on Gnome, but it doesn't have the cruft.

What? In Windows 7, the contemporary version to GNOME 3, all the flashy effects come on by default - or at least they did on this machine. You have to turn them off if you don't want them. IIRC OSX is basically the same... isn't it a little counter-productive having a whole lot of pretty effects if they're off by default?