usable for who?
I cannot image something more usable than a simple e17 + xterm on a Debian to develop my Perl programs.. so I think your sentence must be refined, don't you?
"Muggles"? Please. I've been using Unixes since I was ten years old, and I've steadily replaced all of my user-facing Linux machines with Macs (typing this from my Air, at the moment).
Apple's triumph has been in making technology less aggravating. And that's something that most people can readily appreciate.
