The problem is that the instincts that humans possess today, (ie, maximizing short-term comfort, possibly at the expense of long-term survival) is what got us this far. That cannot suddenly be decoupled and discarded as useless simply because we now live in a remarkably stable environment that enables us to focus on things other than immediate survival.

I suspect that if there were some horrible catastrophe and the human race were suddenly thrown back into an archaic society without any of the technological advancements that we have at our disposal today, it would be those MOST focused on short-term gain who would be most likely to perpetuate their own, and consequently, human existence.