To extend this short form a little bit: at least for me, a key insight of this article was: Depending on the height of your circuitry above the earth's surface,

To extend this short form a little bit: at least for me, a key insight of this article was: Depending on the height of your circuitry above the earth's surface, depending on the area covered by your wires, and depending on whether there was a thunderstorm above you at the time, there might be a fairly huge DC charge on your electrical distribution system. So, the article offers an explanation of why it's really useful to ground one of the two AC wires in the first place: AC generated by the power company may not be the only source of electrical charge on the wires. I must admit, that was not something I thought about before.