It's likely that scammers, or folks like Matthew N Wright, are clinically psychopaths. It would explain much of their behaviour. Most scammers have no empathy or qualms about stealing other peoples' money, but they get just as mad when they lose their own.
Pirateat40 is a classical psychopath. He made up things all day without a second thought; then, he took extra risks and losses to make a show of himself.
Matthew "only" went nuts, scamming for no profit whatsoever. But maybe he believed he had a chance of getting rich? Hard to tell in retrospect. A lot of the things he did weren't very sane.
Goat here just looks for profit under the assumption that his moral stance is irrelevant anyway. It's like your usual corrupt politics; not exactly clean but not a good target for white nights either. While I don't approve of this, it's certainly been efficient in its own way.
Empathy, morals, and psychopathy are only loosely connected. A psychopath enjoys playing with the emotions and trust of others, while a person with less sociable morals just doesn't value other peoples' feelings as much. A lack of empathy is a necessary but not sufficient condition for either.
Psychopathy is a difference in thinking. Psychopaths know exactly what they do and take pride in it, to the point that they show it off. If someone is rationalizing what he did, he's probably not a psychopath. Matthew even tried to apologize; that doesn't fit the image of a psychopath very well.