Imagine if you had to install the OS onto a Playstation or Xbox before you could play a game? No wonder nobody makes money on Linux.
Notice that nobody has a problem with Linux on their phone, because it comes pre-installed. If Valve can strong arm a few OEMs to preinstall Linux on desktops and laptops (against strong MS opposition), they stand to make a lot of money and simultaneously establish the fabled "year of the Linux desktop".
That there are very few preinstalled Linux options is the reason it hasn't taken off commercially. It's the reason Linux drivers are a huge problem. It is why "grandma" can't use Linux. And it's why John Carmack can't make money.