It is software, in Chrome case is just a simple popup, the code is there and it only is visible for OSX because the platform forced the vision guy's hand. The bullshit excuses that is hard to code and test and maintain do not work here.
Also excuses do not work even if valid if you destroy your users workflow, you don't remove system tray, server side decorations and just tell your users to find replacement applications because the ones they use do not conform to the GNOME vision.
Again, if is not a toy you target some users, is your duty to listen to this users and not to impose your vision on them, I am upset when there is no actual testing/research involving actual users and real world work, say when you test your app with "hello world" simple workflows that fail in real world with real users, or you make your app look cool on your expensive screen but looks like shit on real users hardware.
But you are right, GNOME has decided they don't want a part of the users and they are cultivating the perfect GNOME type user, a user that adapts to the software and not the reverse.