If one has a duty to fight for his country, then his country is morally just when it drafts him into the army. If we are morally obligated to give our money to the poor, then the state is justified in collecting that money. If we have a duty to live our lives for the needy, then the state is perfectly justified in collecting our lives and using them as it sees fit. And indeed they are selfish. All of them treat man as a sacrificial animal to be immolated for the benefit of the group, the tribe, the society, the state.
Altruism is incompatible with freedom, with capitalism and with individual rights.
One cannot combine the pursuit of happiness with the moral status of a sacrificial animal. Under altruism, each man becomes a threat to his neighbors, for every man is both a potential exploiter and a potential milch-cow. Altruism creates not a society of independent men trading value for value but rather a constantly changing intermix of masters and slaves. Men do not respect each other as competent, rational individuals but as incompetent men unable to survive on their own. The man who attempts to live for others is a dependent.