Martin,

I agree with you. I'm sure there are a lot of well thought out, informed, scientific studies that support the premise as well. But since I don't happen to have any sitting around let me just propose something off the cuff. While it's pretty simple to eliminate one human being, intentionally or not, it's really very hard to get us all. Nature (and sociopaths) has been trying to kill off the human population (or some specific segment of it) for a long time and has failed every time.

Diversity is the key, whether it be in the genetic make up of humans that thwarts the pandemics, or the diversity of an open society that can improvise, adapt and overcome because of the inherent freedoms of thought and action. It's just really hard to hit the moving target humans and their societies prsent hard enough to wipe them out.

It's easier with monocultures. Just ask the Dodo bird or the Mayans (about that end of the world prediction, what's up with that?). But all of us? Completely? In an instant?

Ain't gonna happen unless our sun goes super nova a lot sooner than expected.

Martin, I've gone beyond your original post a bit but I share your non-pessimism about the world as we know it. Living thru the Philles meltdown of 1964, or Joe Kuharich as the football coach of both the Eagles and my alma mater, Notre Dame, and still retain a sense of optimism about the world means that something in our nature as humans makes us run towards the abyss believing that by the time we get there someone will have built a really nice bridge...