Why TIS? Probably because we are able to sublimate our avarice through them: the guys on the screen act out our fantasies or a version thereof. But also because we usually only see them killing other bad people. Think of the Trilogy. Who do the Corleones murder?: Other gangsters and corrupt politicians, police, and ecclesiastics. Then too there's an immediacy to their actions. They have people to do their bidding and to do it quickly, to acquire money and material goods, and to exact revenge.