The first point of accuracy about this article is the name of the source. Nothing in this world is more true than the "Cult of Mac".<--- This means it was a joke.
On a serious note. Although many of us on here already knew this about all batteries in general, as a teacher I loved how the author used the mattress pumping analogy to explain why more Volts are needed as the charge gets closer to 100% capacity for many of the readers whom may not fully understand general properties of electricity. I often use analogies like these to connect the connect of what I am teaching to concepts in which my students may already understand.