Rarely? Maybe so, I dunno --- but I have personally been one such buyer, so I must respectfully question your "myth" proclamation.
Specifically, we once purchased a fixed week 8 through SMTN at a place in Daytona Beach. It was some years ago now, but I vaguely recall that the place was called "Seven Seas Resort". We offered what we were willing to pay (considerably less than the listing price) and the the offer was accepted and a successful closing did indeed occur. The closing costs were of course exorbitant but the "all in" total figure was acceptable to us at the time. We never actually set foot on that property; exchanging with it twice (back when we belonged to RCI) and unloading it for a bit less than our purchase price, ultimately preferring to buy weeks on the Gulf Coast instead.
I don't think SMTN gives a hoot what their overpriced "listings" ultimately sell for (at least back then, anyhow). After all, they have already collected serious upfront "listing" money from a desperate wannabe seller. If a buyer comes along (...rarely or not), SMTN gets the exact same inflated closing costs whether the "listing" ultimately sells for ten cents, ten dollars or ten thousand dollars.
I have no use for SMTN, but they have certainly (and quite successfully) carved out a nice little niche for themselves, taking financial advantage of desperate and under-informed wannabe sellers while apparently staying (...just?) inside the lines of legality.