I finally took my Mac Pro (2,1) to the dump and went up in stages to OS 10.10.5 (and iOS 9) on all devices in the house (I have 7 kids).
I agree completely with this recent slam on the course of the Mac user interface.
Some of what the author of that article claims, I can agree with, but not his overall theme. I took the changes in OS X and iOS in small bites and got used to them. I think you took them in big bites and the learning curve was steep. I like many of the changes but they are jarring when you jump several versions rapidly. The fonts used in iOS could be less, shall we saw, thin. I'd prefer the option to let the user elect to retain the old skeumorphic style of doing things. I am an old fart and like things that looked like their real world counterparts.
One thing in particular from that article is totally wrong. The chart claiming to be a map of user interface from 1995 through 2015 is really deliberately designed to LOOK confusing. . . deliberately moving objects to different positions in columns totally unnecessarily adding confusion. The author drops WYSIWYG after the 2008 column as though that actually is an actual occurrence, when Apple still uses WYSIWYG in its user interface. The author does this in many instances, when Apple actually incorporates functionality into a more inclusive function. . . but to continue it or show the inclusivity would not advance his thesis. The author blithely assumes that the designs of OS X and iOS are also based on the same theories of user interfaces, when they are not.