I somewhat agree.

But fun fact, CEOs and senior executives are disproportionately more likely to exhibit psychopathic traits.

Also, I agree that not everyone would be killed in such a scenario. Someone would get lucky. There are people who only eat food they grow themselves. An extreme minority, but they would survive. There are also tribes of humans which receive very little contact with the outside world. Plus, plenty of people have bunkers, and are prepared for, at least, some of the scenarios, and some might just be immune.

>And hence would have the resources along with motive to give the murderous monster their just desserts.

This is dependent upon it being just one person. What if it's a large cult? A rogue nation. They don't need to wipe everyone out, if it's anywhere near 90%, and they aren't affected? They just outright win all future conflicts. Just picking up all the bodies would take years.. Let alone getting things like food production and other essentials going. Not to mention the loss of human skills.

Agi could accelerate a recovery dramatically, but the rogue group would also utilize it.