It was the wrong lesson because the focus was entirely on who made the most money. And because it was funny money, the losers didn't actually suffer any real consequences other than the psychological pain of not being the winner. It flattened the risk-reward curve to the point where there was no real difference between losing 90% and simply coming in second. IMHO that is the wrong lesson (though I also note in passing that it is a philosophy that many Americans seem to subscribe to).