Both pilots were fatigued as a result of their greed and the CVR of that flight demonstrated just how many mistakes they were making as a result and ultimately they made wrong decisions that resulted in them stalling the aircraft killing all on board ... and all because they wouldn't pay for a hotel and/or a flight.
GREED?! Utter nonsense! The FO was on $16,000 a year, the Captain around $40,000. Having flown for the regionals in the US for five years before coming back to Europe, I can tell you this is the norm and is in no way caused by greed, but by necessity as many young pilots can barely afford to live.
The crash was indeed caused by fatigue, but also very poor training at the operating airline, Colgan Air. The captain in particular had a very chequered training record.