I am reminded of a quote from the founder of Revlon cosmetics. It went something like: "in the factory, we make cosmetics; in the store, we sell hope".
I bet many people, including myself, are falling prey to this when we buy a tiny frag of something that we hope will grow up to a large colony of something beautiful. It's an aspirational thing.
Put on top of that the dynamics created during ebay auctions or live sales (those are as much about "winning" as they are about "shopping"), and you have a somewhat addictive situation.
It doesn't seem to be in the interests of the power players in the industry to do anything to try to let the air out of the balloon, so as long as people show up with their cash, with hopeful eager smiles on their faces, it will keep on rolling.