Value is more than one thing, arguably. You kind of have to go back to first philosophical principles to unpick this. Which I guess is my point - if one's goal is the expansion and longevity of human civilization (which I think is reasonable) then it's not clear at all where the rest of organic life (which we compete with) fits into this picture. If the best reason to preserve it is "it's pretty to look at" and "maybe we'll get some medical advances" then let's just admit that. I'm only suggesting that this is something about which reasonable people can (and have) disagree.