Pretty sure that "electricity runs for miles.... then gets to the magical power cord..." is his sarcastic way of trying to say something without ever having to, you know, come out and say it.
Since he's afraid, or more likely simply hasn't thought it through, what he's trying to say is those last few feet can't possibly matter. Or the other way he might like to put it, if he would actually put it instead of sniping, you'd have to replace all the wire to the dam. Both of which seem to have a grain of truth even though they are ultimately misleading.
Its true every foot matters. Might even go all the way back to the dam for all I know. It certainly goes as far as the drop line. And according to a couple very reliable listeners it goes as far out as the neighborhood transformer.
Of course the 5 ft of power cord matters. There's nothing magical about it at all. Its simply that some amount of degradation happens every inch of the way. Minimizing it for 5 ft is an improvement. I've done that in stages all the way back to the step down transformer, then to the panel, then the panel itself, and the meter. Others like I've said have gone even further. For every foot you do the sound improves.
People wonder and get triggered and argue when I say how fantastic it sounds. But you know what? Its only the people who haven't tried these things that get all worked up. The ones who've done it, we all know.
