Antoniou seems to be in the awkward position of being forced to debunk the myth she had a large part in reproducing, though not creating.
She also talks about the myth of the Old Guard, criticizing the belief there was an elaborate hierarchy of initiation for gay male leathermen back in the 50s and 60s, and especially critiquing the idea that this way of doing kink, if it ever existed, should be regarded as an ideal today.
What the myth of the Marketplace, and institutions like it, says to me is that a lot of people yearn for initiation. They want somebody out there to recognize their innate specialness, give them the Call to Adventure straight out of Joseph Campbell, and be swept off to the Realm of Magic. It’s what drives Harry Potter and Twilight and The Matrix. While I’m hardly an expert on the Marketplace, I get the impression that Antoniou wrote it in part to critique that myth and ended up promoting it.