I don't want to be too dismissive because something about the article rang true to me, but I don't know that I buy the whole central conceit that the idea of a stack can apply as universally as this article needs it to.

Apple's networked services have often struggled. But are they really higher level than the things Apple succeeds at? Asking whether enormous distributed data stores are higher level than Mail.app just seems confused. It's different, and it brings new challenges, but are they part of the same stack? And is the data ingestion and sanitizing that Maps struggled with higher or lower level than the client that was basically ok? You can multiply these questions and I'm not sure you can get good answers.