In any other context I would agree with you, but in software, the point the author is making is quite true.
MS would include superfluous icons because they observe it in other software and can't think for themselves, or they would omit superfluous icons because it never occurred to them in the first place.
Everything Apple does is carefully considered, good and bad.
I take the latter every time, because I understand how bad things are in software. I know it's unrealistic to be as choosy as I want to be.
Microsoft has (and had) some amazing designers. They came up with Metro, which was the forerunner of the flat design that everyone loves/hates now.
When you say carefully considered, you're going with the the Aristotelian process that led him to argue that feathers fall slower than rock.
It would have been a very easy thing to test the people outside there bubble.
Apple's own design guidelines originally said not to do the thing they did (and which they are now once again saying not to do).
Couldn't Apple have just, like, talked to the people who originally wrote the guidelines? Why do they need to re-invent the wheel? Will Apple forget again in another 15 years and need to re-run the experiment, taking us all along as test subjects?