Maybe I'm not smart enough, but I don't get it.
Human extinction due to AI = human self-destruction, assuming we are talking about an AI initially created by humans (not from some alien source).
If the assumption above is correct, then human self-destruction at the hands of an AI is better than most forms of human self-desrruction (imo), for at least the knowledge we generated during our short time here might be carried forward by the AI we created.
I enjoyed this.
I really like your point about automation changing the balance of power between elites and workers, potentially eliminating the threat of strike or revolt.