Mary is saying “talk down to your audience because they are dumb” and she’s almost right. (And, as we've discussed before, and as she mentioned, book reviews and discussions of authors in general have a very limited audience here.)
But is that what you want to do? Talk down to your audience?
She’s also telling you to do almost exactly what you’ve done but in a lesser way. You have given the reader that “context” in the title and subtitle, haven’t you? You simply haven’t spelled it out for them in an elementary-grade level.
I believe I’ve mentioned to you that LEVEL is starting that book club thing and opening up a test run in November. See who is joining up even if you don’t do so yourself. Those are the people you are or should be writing for, not the broader Medium market that Mary is talking about. That and continue plugging away at the book pubs, especially where you first published this. Don’t give up on them just because you first pieces failed. That happens with all new writers. It isn’t the fault of your writing. It’s the fault of your newness.