The problem with his article besides being obviously wrong in retrospect is his focus on usability as a defining factor for the success of the product.
Usability and simplicity isn't why a product succeeds, it needs to be understood in context with engineering, marketing, luck, timing and so many other things.
The iPhone succeeded because at the time it was such a fresh breath of air.
True, but I actually think it succeeded very much because it was the first usable "smartphone". The author of this blogpost didn't realize this. Although he could do exactly same stuff on his old Nokia N-series, it wasn't until my dad got an iPhone that he began sending mails, browsing the web and listening to music on his phone. Now my mother's got one as well and she's doing the same.
Usability and simplicity isn't why a product succeeds, it needs to be understood in context with engineering, marketing, luck, timing and so many other things.
The iPhone succeeded because at the time it was such a fresh breath of air.