User blog comment:MeDeoPal/On the Origin of Titans and Shifters/@comment-155.158.60.209-20131118233724

Chapter 0 was made by Isayama Hajime, the original author and could be viewed as the basic idea for the series. And the theory that the titans were created to extarminate humans and make the perfect being exist in the world would make a lot of sense to me.

It'd explain the behavior of those who know what's going on and why they are so obsessed with their beliefs and going against humanity.