It seems clear to me that this article is aimed at science educators who do have a solid understanding of electromagnetism, electronics, etc., but struggle to teach high-school and college-aged students due to widespread misconceptions about “electricity” (some of which seem bizarre to an expert). The article explains what those misconceptions are because it is assuming the reader would quickly understand the scientific (or ontological) error and spend the bulk of their thought on the educational side.

This article is simply not aimed at you, it is directed towards experts. So your complaint is a bit like complaining that “C# In Depth” doesn’t sufficiently explain basic syntax.