It's not even about Mac OS X vs GNU/Linux, I'm not using any desktop environment on my computers (no Gnome, KDE, XFCE, …), my graphical environment is composed of a minimal windows manager and a small taskbar. I don't need anything else. I just checked and I don't even have a graphical file browser installed on my laptop which I've been using it for several years now. I spend my time in terminals, Emacs, and my web browser.
I know that this is not the case of every person who's working with computers, but I also know quite a few people in my surroundings who use the same kind of environment (and to my knowledge we're all pretty pleased with our hardware), so I'm convinced that I'm not an exception either.