But desktop OS vendors seem to still be operating under the paradigm of making their desktop environments as approachable by computer novices as possible. Maybe still a good business decision, but the future for desktop OSs is clearly with professionals and enthusiasts, and it's my hope more advanced human/computer interface approaches will follow.

You can have better window management facilities on Linux, but you have to choose between software that copies the mainstream paradigm of, as you say, pushing new views onto navigation controllers (and I'd add using tabs/split-panes built into the window itself instead of being offloaded to a more sophisticated window manager), or software that's quite rough around the edges.