Comment by soiltype

The same reason you bandage a stab wound instead of letting the body decide what it wants.

It doesn't want anything or have the ability to choose its responses to changes. Which is exactly why we are the legal guardians of natural ecosystems, by the way - have you not heard of lands and waters protected from certain human activities? The fact that we don't currently stop ourselves from propogating honeybees into ecosystems that can't fit them is not an indication of anything except our failures.