Can you give some examples of the mistakes?
One of the fun things in electronics is when someone builds a small signal amplifier then wonders why the output is lower than calculated with zero understanding of source / load impedances. Because no one taught them about that.
I found a list of (independent) errata for the 2nd edition [0], presumably because it was used in a class. I see one note about the "Rule 2" for transistors but, to me at least, it looks like the author just forgot a "not" in the sentence.
In general, the errata looks like what would exist for a textbook that was written by a person. It has mistakes, mostly typos but just a quick glance doesn't uncover some fundamental lack of knowledge from the authors part.
I'm no expert in electronics, so I don't have enough confidence to make a statement about the competency of Scherz, but your assessment seems hyperbolic.
The only way to outline this is to do better which I may do if I ever get the time to do so.