Post facto? You reeeeally believe Apple hadn't build tons of prototypes in various sizes PRE FACTO (sic), and made extensive research in what is more comfortable for the largest majority of people?
Stating that this "seems like something Apple would consider" is a far cry from what this blog post does: take one data point's worth of design value from an existing design for one user, extrapolate that to be one of the lead drivers of said design for all users.
I'm all for giving Apple's designs as much credit as possible, but it's still a far cry from even that to "wow this thing about the design I just noticed that works for me must have been something they considered for the populace at large."
The author made a very astute point that I haven't seen mentioned online before (but one that immediately occurred to me when I heard people bitching about Apple not going to 4+ inch screens). His single data point illustrates a general problem: one handed operation for people with a wide-range of hand sizes.
Remember, Apple sells one basic body shape to its entire market. No single Android phone sells anything comparable to as many units as the iPhone. The body shape has to be usable for 95% of Apple's potential market, which includes everything from teenage girls to grown men. Apple undoubtedly thought about exactly the problem the author raised.
I was looking at notebooks and thinking I want a big screen but with the keyboard in the center. I want my hands write in front of me, but I don't want to look to one side. I 'know' apple do it that way. Then I found an HP that was almost like that but the F was more left than the J was right, which are the home keys, so I thought still no good. Then I looked at the Apple and it was the same the F was more left that J was right. So I decided it must be right to do that, because Apple know best.
Yes, it's a "No True Scotsman variation" that takes into account the fact that a particular company gives TONS of attention to detail, builds lots of internal prototypes, and values usability and good industrial design ("how it works") greatly.
The fact that you don't know if something specific happened does not mean that you cannot reason about the high possibility of it happening given the historical information you have available.
Given what we know about Apple, Ives et al, what exactly do you believe of the two:
1) Apple picked the dimensions at random or without thought
2) Apple studied to find the best compromise for the device's dimensions
