Comment by mrob

Humans already eliminated rats from Codfish Island/Whenua Hou, and that's just to protect some rare birds that people only moderately care about. It's not like we had some overwhelming reinforcement-learning drive to single-mindedly achieve our goal. Any unbounded goal (e.g. "find as many busy beaver Turing machines as possible") necessarily requires killing all life, because life requires resources to sustain it that could be instead used to achieve the goal.