Why is Collectivism Superior Moral in Socialist Views? -Why would it link to Socalist's view on Human Nature?

-It creates Cooperation and Prevents the Aggressive Conflict Individual's Self Striving Behaviour has caused. -There are Positive and Unifying Effects on Society, which provide Moral and Economic Benefits -This links with their Positive Human Nature as they assume Humans are Naturally Social Altruistic Beings, so Collectivism is just a Natural Development