Some bits missing.
This article appears to be a partial look at the range of distros available. Yes, Linux Mint and Ubuntu are popular but what about some of the other branches?
Mandrake pioneered a lot of the user-friendly things now found in Linux distros and to my mind diskdrake still takes some beating when it comes to partitioning. After the regrettable demise of Mandriva/Mandrake there have appeared a number of derivatives such as Mageia, PCLinuxOS and Rosa. They have all inherited the Mandrake tools to make life easy for new users and are in the top rankings of Distrowatch so they must be doing something right.
My choice is PCLinuxOS.
As I say it is simple to administer and does not have the beast known as systemd entwined around it. Added to that PCLOS is a rolling release that seems to have cracked the problem of keeping the distro up to date without breaking anything. Added to which it does not use sudo as the default which gets a thumbs up from me as I consider the way Ubuntu uses sudo to be an accident waiting to happen.
So yes, the distros mentioned are worthy members of the Linux family, but the article only really tells one side of the story.