The article alludes to Guy Kawasaki's 'evanga-list' back in the 1990s which seems to be the source of the "Everyone thinks Apple is doomed" meme. I don't know if anyone has written up the whole story, but it's been discussed on various Mac fora over the years.
I see the claim mirrored in your article, also stated as fact:
Strangely enough, the people doing the most service to the narrative of Apple’s impending “doom” are Apple apologists themselves.
Is it discussed or supported beyond that? Sorry if I missed it.