"It was on display at the bottom of a locked filing cabinet stuck in a disused lavatory with a sign on the door saying beware of the leopard."
Linux is difficult to use for the kind of person who is downloading software from Download.com - "compiling binaries directly from the source" might as well be Klingon to them. Frankly as a geek I'm much happier with my Mac and Windows machine than I am with Linux. Even now things like the Linux Standard Base not being utterly standard demonstrate that Linux is still aiming for a different market.
There is a gulf between "my Mom is running Debian, she thinks it is Windows, hehehe" and "able to manage a Linux box even remotely competently".