Well, hacking bitcoin blockchain is a bit hard. But hacking exchanges is so easy..
For greed: "to the moon" and "hodl" slogans are, by some point of view, a sign of greed. Volatility and "OMG huge profits" are the reign of traditional system, that now is heavy working on bitcoin market.

Think to this: the same people that consider bitcoin as a sort of bank-killer, where the same that celebrated when banks supported CME future. Then, when moon didn't arrive, they started complain because banks supported CME futures. It is a bit crazy, and definitely a bit insane...