Why "Hot Sellers" aren't so hot for sellers

Just about any time people contact me about learning to sell on eBay or starting an eBay business they are wanting to sell what is "hot". I don't have the hard numbers in front of me, but I would estimate that about 80% to 90% of my students have been people wanting to sell designer handbags or jewelry. I see posts on discussion boards time and time again from people wanting to sell the latest electronic do-hickey or ipods. why?
eBay has done a fantastic job marketing this to people. They publish a list of the hot selling items and popular searches (eBay Pulse). They tell success stories about sellers that have a million feedback from selling cell phone accessories. The list goes on. All this makes new and potential sellers believe that this is where they will find success selling on eBay.
Ever heard the rule of Supply and Demand? The more that is available (supply) the less demand for the product therefore the price goes down. From eBay's point of view, an abundant supply is a good thing. They get more fees from more sellers listing the product, the saturated market pushes down the price therefore more buyers come to their marketplace to buy stuff at the cheaper price, leading to more money again for eBay in final value fees.
Now, look at it from a sellers point of view. Selling the "hot item" isn't so hot. The model I just explained doesn't benefit the seller. The seller is better off selling the item that is scarce, therefore in demand, so that the price goes UP!
This doesn't necessarily make eBay bad, they are just doing a damn good job of looking out for their shareholders. Now.... you go and look out for yourself and find something scarce to sell.