You can't just say Linux instead of Gnome.
Linux, the operating system is just the kernel. It's not like in Windows where the GUI stuff is all part of the OS. People could be running anything, it doesn't have to be Gnome. And lots of people I know don't run Gnome or KDE (since they are a bit bloaty.)
All MS did with their start button is put a very ugly skin around it. Not much innovation if you ask me. A gnome panel can have something similar to a start button but it's removeable and moveable, so it can be placed anywhere, on any panel. It's optional. Even the entire panel is optional. Many other window managers (like fluxbox/blackbox) launch their 'start menu' by rightclicking on the desktop for example. Then there's many NextStep'ish windowmanagers out there that many people use, which have floating boxes on the edges of the screen which can be buttons to launch applications, or drawers containing a bunch of application launchers, or entire programs running in a tiny box (dockapps). Gnome may be most commonly pre-installed with many distributions but i'd say it's far from being "The Linux windowmanager" that would tick allot of people off.
Calling video's like this Linux usability tests, is just more misinformation that can add to prejudgmental ideas non experienced linux users can have. (eg: I don't like linux, because I don't like gnome.)