I wish the authors had spent a few hours more honing their argument, because some of the points are really good.
Where it fell flat for me:
* The post was much too long. I was intently reading but soon realized that it was all over the place and started having to skip through to try to dig out the main points.
* They admitted that they weren't even working at Apple during the time when it was designing successful products.
* They admitted that iOS 9 solved many of the problems quickly at the end without saying which ones or how they failed and while introducing new problems (memory?) that only served to confuse the reader.
* The authors' argument was incoherent. It seems to be building up reasons why Apple's design was bad, but they are all over the place. "It's just bad" is not an argument. Lay the groundwork. Provide evidence for each point and evidence against arguments against those points. Tie it all up.
Some of the information in here would make great articles on their own, e.g. I'd like to read a full criticism of Apple's new font, how the Human Interface Guidelines list changes over the years and how it could be better, and the whole Dieter Rams piece would have made an excellent article even outside of the context of Apple's failures.
I think few that have been using iOS and OS X over the years would dispute that Apple has dropped the ball since Jobs' death. While much of Apple's design still trumps others', others have blindly followed Apple and done an ever worse job. (I'm looking at you, Windows 8, which was a reaction to both iOS's use in the iPad and the terrible AppStore trend introduced in OS X.) Hopefully, Microsoft, Google, and others have realized by now that leading and innovating doesn't mean copying or reacting out of fear to Apple's direction- it means hiring extremely creative people that understand user-centric design.
But, even though there are problems at Apple and with design worldwide thanks to Apple's mistakes, the authors of this post haven't made it much clearer why they dropped the ball or how we can all understand how to avoid those problems.