Now you have some inkling of why when the "Was Don Lancaster Really A Guru" thread appeared I was ROFL.
His Active Filter CB, TTL CB and CMOS CB were his major works. But with the (according to Dave) 32 others he wrote, I'd say its a safe bet he sold close to 10 million books in total. Quite possibly more. If that is is not superstar status for a tech writer, I don't know what is.
Realistically only 3-5% of the population has the interest and motivation for STEM. And as a society, that's all we need. The same thing applies to the skilled trades and other professions. In the 70's and 80's if you did not have several Don Lancaster books you simply were not STEM material.
You have really got to know the subject to write that well on complex topics.
BTW What printing are your copies? I have a very worn 2nd printing of the TTL CB which I bought and a near new 3rd printing which I scavenged at work. Both of mine are the original green cover.