Just World Fallacy is incredibly seductive. If there are rules to follow, it won't happen to you; so therefore if it happens to this other person over there, they didn't follow the rules. Cthulhu-like existential horrors are only fun in books, not when they're revealed to be the world you're living in, so people accept the fallacy because the reality is just too awful to bear.

I understand it. It's completely inhuman, but a lot of fear-driven things are. (And the reality that only if significant enough numbers of people give up their just world security blanket will real, lasting change happen makes me want to take up drinking as a hobby.)