There's a lot wrong with the article, I gave up reading it because it's mostly fluff, including this part: Current theory holds that prehistoric hunters drove these species to extinction.

Here's a Nova episode that shows the human caused extinction hypothesis to be inadequate, more likely it was an asteroid: http://www.pbs.org/wgbh/nova/clovis/

Anyway, point is, humans can rationalize anything -- or even nothing.