It's not about being an idiot at all, but how these corrupt bastards are using this as an opportunity to increase their own holdings behind the scenes. If you know for sure that the market will tank badly, you'll sell every satoshi that you have, and then simply use the MtGox coins to crash the price further down, at which you will be buying back your own coins. I am sure if they did everything well, they more than doubled their own Bitcoin holdings. These people have no moral standards, and thus aren't shy to use everything they can in their advantage to benefit financially. This market is literally infested with such individuals. Mark, the fat fuck that he is, became more wealthy than ever before.