Re: Gnome??
Then...there is also the possibility that Linux has never made it big for desktop use, simply because the majority of computers users just really don't care about it.
As early as 2002 I read an article that claimed Linux would never get big on the desktop. The author argued that, just as Microsoft never tried to get mainframe admins to switch to Windows, but rather took advantage of a paradigm shift (from dumb terminals to desktop workstations) to rise to prominence, so would Linux dominate the next platform, whatever it turned out to be.
The "next platform" turned out to be a mix of technologies: handsets and tablets on the user-facing side, cloud-y servers on the backend, and the web sitting somewhere in between. And to a degree, Linux does thrive on it, though the dreams of unquestioned dominance have obviously been exaggerated.
So perhaps arguing "who lost the desktop" is missing the point, and we should rather be asking "how to win the mobile client"?