Most people who play 3D games use a console.
The rest are a minority.
And everybody else uses their computer for NORMAL activities -- business applications, web browser, email, etc.
To believe that GAMES are the MAJOR stumbling block to the platform spreading is very misguided.
If you want linux to catch/spread, you need an APPLICATION that ONLY works on linux, that people *MUST HAVE*.
Look up the history of the SPREADSHEET and see how IT impacted adoption of computers.