---egalitarian ethics define all people as having more or less equal rights to status and resources, regardless of individual ability. Egalitarianism, in turn, has powerful long-term implications for the costs of reciprocity, for giving takes place with the knowledge that the recipient cannot use assistance received to gain disproportionate social, economic, or reproductive advantage, to usurp the resources of others, or otherwise dominate them. Those who seek to do so are quickly levelled.The above terms of reciprocity, held within populations that pool risk, make their characteristic marks on forager economies by inhibiting competition and capital accumulation. (Polly Wiessner, Taking the risk out of risky transactions)
I guess it's pretty obvious that egalitarianism tends to inhibit competition and capital accumulation. People have been so valuable resources, that the masses, the demos, have been succesful in more or less quickly levelling the capitalists. Egalitarianism is not so worried about those who have too little, but about those who have too much. You can let the weakest ones die, but you cannot let the strong get too strong.