You asked if people don't learn? Well most of them do learn actually but the mindset to this so called Ponzi scheme that most people have adopted is that, they know it will crash, let them just get in early and then get out, with the hope that it doesn't crash at their turn. Guess what, it crashes on them not because they got in late but because their greed has kept them in there.
Nice write up.
RE: Those who fall for Ponzi Schemes are driven by greed, desperation, & a lack of planning