Neither capitalism nor communism assume that their proponents are immune to greed. Capitalism was developed as an improvement over (European) feudalism and mercantilism. The idea is that division of labour expands the quantity and diversity of goods that can be produced. Communism is similarly supposed to be an improvement on capitalism. Here, the idea is that centralised planning can improve the distribution of the produced goods (and further improve the quantity and diversity of goods).
Neither capitalism nor communism assume that their proponents are immune to greed. Capitalism was developed as an improvement over (European) feudalism and mercantilism. The idea is that division of labour expands the quantity and diversity of goods that can be produced. Communism is similarly supposed to be an improvement on capitalism. Here, the idea is that centralised planning can improve the distribution of the produced goods (and further improve the quantity and diversity of goods).