It is. It is only our arrogant individualistic capitalist ideology which pretends otherwise. Cooperation, mutual aid, these are principles that life on earth has found to be beneficial. Biologists and anthropologists understand this. But economists think so highly of themselves that they see no need to study history or modern psychology, so they come up with equations they think describe reality, then ignore evidence which contradicts their models. The result is predictable. You get ecological catastrophe, a breakdown of social trust, and the breakdown of society itself. But oh how we lived like kings before the music stopped! Or maybe living like cancer is more appropriate, sucking up resources, growing rapidly, and fucking up system-wide dynamics. There's a reason why selfishness has historically been viewed as a negative trait, and it's instructive that a society as sick as ours lives by the mantra, "greed is good!".