Linux is never, and I mean never going to be a legitimate alternative to Windows or MacOS on the desktop under the current paradigm. "Switch to X desktop or distro" means less than zero to 99.9% of computer users (probably a few more nines in there too).
"Oh but the Steam Machine!" essentially no one who uses that will actually care what the OS is, it's a shell and a very specific one to do a single task, no-one is buying it as a general purpose machine they can do their taxes on.
