Windows and Mac OS X are the only sane alternatives for developers that care about desktop applications and developer friendly toolchains. Same applies to iOS, Android and WP.
The other alternatives feel like only the CLI and daemons matter, stuck in a PDP-11 view of the world.
Then again, NeXT was the only UNIX based OS with an alternative culture regarding developers tools and UX.
KDE is the only environment that can match in terms of tooling and UX, yet it is lacking some serious love nowadays.
I want my developer and user experience to be a Xerox Star and not a PDP-11.