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.

> the rest of organic life (which we compete with)

Here is the issue: it is more than mere competition. We co-exist in a delicate balance with the rest of life, or at least we used to. Now we threaten to destroy them, and the planet on which we depend, exactly because of this implicit belief that we compete with them instead of relying on them.

I think we need to engineer this balance. The ones we need we keep; the ones we don't, we don't. This is basically bioforming.

I agree, and we should probably understand it before we change it. It was already engineered by natural selection long before we gained the capability to alter it. Now we are in the process of destroying it by accident as a byproduct of thoughtless growth. If we want to survive we should understand it and then carefully cultivate it for maximum performance.

I agree that we shouldn't destroy value, especially by accident. My original point was that having this conversation in engineering terms is the only sensible way to have it.

Why is the expansion of human civilization desirable?

Why does preservation of human civilization depend on exterminating wild nature?

> If the best reason to preserve it

The reason to persevere organic forms around us (plants, animals, fungi, bacteria, etc.) is rational self-interest.

Bacteria are necessary for our bodies' healthy operation. Organics generate the oxygen we need to breathe.