Okay, here’s where I admit that I pee in the pool.
My highest-level academic training is in theatre history, which can be approached from several angles but because I had a strong interest in cultural materialism and pop culture, I tackled from that angle (along with statistical semiotics, not wanting to risk accidentally becoming one of the Continental theorists who extracts six gallons of conclusion from a pint of evidence).
I also write popular fiction (in the sense of “for ordinary readers”; you may check Amazon numbers as to how popular it actually is).
This means I find myself, whenever I can’t avoid it, in the company of pop fiction writers. Nearly all of whom “know” vast amounts of raw unadulterated flat-out false crap about popularity, quality, etc. There I will be at a table hearing, “Shakespeare wrote for ordinary people and he was a best seller in his day” (for Shakespeare you can substitute Dickens nearly as often, though I’ve heard a good round dozen others, including my favorite preposterous one, Moliere) …
The number of things we don’t actually know one way or another, know not to be true, or aren’t meaningful at all within those quote marks is truly breathtaking.
My other favorite is all the various versions of “all plots are the same” or “there’s a law of plot structure that goes back to the Greeks” or whatever it is that asserts that there’s some one kind of plot that has always been the one kind that’s always been popular (usually with the assertion that the writer who is speaking is therefore “producing the classics of tomorrow”, another statement that contains far more errors than it does individual words). The most common origin of these one-size-fits-all-because-I-think-an-extremely-narrow-sample-in-space-and-time-is-all “rules” for plot is in late 19c playwriting manuals (not the ones you’ll find in antiquarian libraries – the specialized ones that theatre producers handed to playwrights under contract for 2-10 scripts per year), and the most common attribution seems to be to Aristotle.
Part of why I try to avoid my fellow writers in too large and inescapable doses. It’s like being a biologist who studies human nutrition at a an alternate health conference, or a planetary scientist among astrologers.