Earlier quoted context omitted.
Surely you must realize that this is the same argument people have been making for close to 15 years, and not much has changed. So that should answer your question about the OPs point.
The main reason most people use Windows is that Dell, HP, Lenovo, Acer and Toshiba make it incredibly hard to buy a computer without it. Go to HP's site now and see if you can get a notebook with Linux preinstalled. Most people would be perfectly happy with a Linux machine (I can tell you my mother is) and had hardware manufacturers given even some slight support (instead of building dozens of models seemingly design…
Because it is neither rock-solid nor stable. It changes too much, too often, in an irregluar, unpredictable pattern, so major software makers refuse to target it. Without software, you dont get users, and without users, hardware makers wont bother to preinstall, etc.
Linux will be able to win big when they start putting a stronger emphases on backward compatibility and start supporting releases for 10 years, like Microsoft does, so that users dont have to reinstall distros every 6 months just to be able to install a new version of s single app.