Yeah, and Android is also "Linux" which makes is the most popular OS in the world.
Very fat sarcasm aside, Android is not Linux (aside from a forked, heavily patched, frozen version of the Linux kernel), ChromeOS is not Linux (it's an atomically (!) updated immutable (!) Linux kernel based OS distributed by Google), and SteamOS is also not Linux (see ChromeOS above), if we are talking about Linux distros containing
* upstream kernel with minimal changes
* glibc and other usual libraries
* Xorg or Wayland compositors
* Desktop Environment
* Packaging system that allows to install/update/delete any package
This article is just a huge piece of cope. Linux (distros) have always been crap and will continue to be crap for the average Joe and that's the exact reason the Joe doesn't touch them.
Linux fans will obviously downvote me to hell, but I'm OK with tribalism and zealotry because this post contains nothing but facts. You cannot call just anything using the Linux kernel "Linux" because it's just a kernel which in itself is 100% useless without usespace. And 99% of people out there (who has ever known anything about operating systems) think about Linux distros when they are talking about Linux.