To be sure, I invest in order to see a return. That's greed, I guess? Or maybe not?
I think having (unrealistic) expectations of doubling your money in anything shorter than ... about a decade ... should be sending up red flags for anyone. "Make money fast" should fire the same neurons as "Put it all on zero and spin".
I had a friend who began to believe he had written code that could play the stock market and rake in the cash on trades (he was testing it on historical data and doing very well). The best way I could try to reel him in was to simply suggest that if it were so easy, everyone would be doing it.
Same goes for any get rich scheme.