No, I'd tell you that you are taking a statement about one class of books and apply it to a different one, with different target mission and utility.
Technical documentation has a very narrow scope, and deeply technical writers. It's target users also are engineers directly applying what they read or looking at it for reference to something very specific.
It hasn't been historically the province of any hack and/or snake-oil salesman.
Nor do people buy book after book of technical documentation trying this and that fad to no avail to fill some psychological void. Hmm, now that I read this last sentence again...
