Upon further review, I have to question some of the "reporting" that Mims did. He said it was a 45-minute lecture, with questions after, and yet he quotes only a few minutes of it. So how can he be sure the "vigorous applause" was for the ebola comment and not for the other 40 minutes of the lecture? Mims does admit "After a dramatic pause, Pianka returned to politics and environmentalism. But he revisited his call for mass death when he reflected on the oil situation." So it seems Pianka was discussing the politics and environmentalism of overpopulation, and only touched on his "solution."
Obviously Pianka has some radical thoughts and I don't defend them, but perhaps he is resorting to an extreme view to get the point across that the human population on earth, and the growth trends, are unsustainable when compared to the resources we consume. Sometimes you have to shock people in order to get them to think about, and remember, things. Perhaps Pianka has a screw loose and really believes in his solution, but that doesn't mean the underlying problem doesn't exist. A problem is with the individuals who focus on the shock and don't see the broader picture; obviously the message is lost on them.