Animalman and DuplicateMan, my wife gives me the same arguments all the time. I don't think I'm making a bad assumption, though. These aren't just human foibles but behavior we see in every form of life with DNA (i.e., all known life). It lives at the expense of other things, multiplies as far and as fast and as often as it can, and consumes resources until they're gone. What looks like conservation in the natural world is actually the natural world pushing back on an upstart population. Equillibrium isn't a foregone conclusion.
I can conceive of a civilization like the kind you guys describe, but I don't think this would be the one that partakes in interstellar travel. I see this civilization as sitting around all day on an idyllic planet, contemplating the deep mysteries, and saying, "Well, that was fun," when its star finally dies out. The proposition of space travel involves a huge expenditure of resources no matter how you slice it, and biological creatures don't expend resources without expecting a return.
Look, I'm all for taking the U.S. military budget and giving it to NASA. That we aren't already on the moon and Mars and sending drillers to Europa to categorize the biolumisescent alien jellyfishes is a deep embarrassment to the Carl Sagan in me. But the most fit in our society would rather go after more practical rewards with more immediate benefits.
