The 'seven deadly sins,' the human failings recognized by the Roman Catholic Church during the Middle Ages, were pride, greed, envy, anger, lust,...

The 'seven deadly sins,' the human failings recognized by the Roman Catholic Church during the Middle Ages, were  pride,    greed,   envy,   anger,  lust,  gluttony,  and sloth.  Why are these traits likely to be viewed as dangerous by people who live in an agrarian caste system with strong traditional culture?

Are these traits a threat to today's capitalist class system? In what ways might most of them (perhaps all but sloth) be necessary to our way of life?