I agree on your criticism on a human nature point of view -- we only do something if we get something in return. The question I raise is what system shall we use? Btw, don't give me the communism crap. We know too well communism is at fault for enabling the most death. ON paper I love communism. In execution, it's asinine due to poor accountability, durability and robustness in empowering the human experience.
From a Christian perspective, there is a book by a Christian Theologian called The Cost of Discipleship. It was groundbreaking when he wrote it. Basically, the author points to the suffering and death the disciples of Jesus went through. In addition, we also highlight the suffering and death the early Christian went through. Why the heck would anyone do such a thing if they are normal - die a torturous death? Either they are crazy or they are right. In my studies on change and innovation I see so many people feel strongly about something that they are self-sacrificing to it. It is as if their entire purpose is driven to that one thing. Take the invention of liberty. Liberty was invented by the wealthy and intelligent. The people who benefited most from liberty are the poor and ignorant peasants. Why would a wealthy and intelligent person undermine his own position for the poor and ignorant peasant? That's unreasonable. Regardless, it is where society went to. It is as if it was right. In modern discussion today, you see some philosophers have come to argued that the rise in English speaking as the hyper-power is based upon Moral Reasoning and not Rationalism as some have point to. The Germans, French, and other in the area operated under rationalism with. Moral reasoning is something the English speaking nations operated under. Who inherited the world? The righteous who operated under moral reasoning. There must be something evolutionary compelling about moral reasoning - do what is best for all, all the time, even if it cost you. I'm still scratching my head on this as I learn to understand more about myself.