The post ignores, why there are so many different FOSS licenses, the thing is people have interests and sometimes these interests are not compatible. So there is a place for MIT licenses, namely if you want as much adoption as possible, and there is a place for copy left licenses, if you want to protect the associated rights of copyleft. This is probably most visible in the “anti-tivoization” section, which concludes

     The license restrictions of the AppStore, Google's Play Store
     and similar distribution systems and the GPLv3 are just not 
     compatible.

The reason for this is Apple, Google and others have their interests, namely controlling a platform and enforcing whichever restrictions are mandated by their interests.[1] On the other hand, the GPL[v3] tries to protect the freedom to tinker for the owner of the device, the ability not only to see the source code, but also to modify and run it. So the absence of GPLv3 licensed software on iOS is actually proof, that the license is working as intended.

[1] Some examples of these interests are: Enforcement of DRM, trying to create a 'more secure' environment, having a consistent UX, etc.