After I wrote it I backpedalled in my mind, but didn't bother to correct myself.  I think that you are correct - it would be exceedingly hard to kill ALL of the humans on Earth.  Hell, I don't even think they can kill all of the mosquitos with that gene drive trick they invented.

But I do think that gain-of-function research will never stop, and as time goes on, we will suffer more and more from this kind of thing.