You know, I find this one disgusting, too. However, I saw it posted by somebody I know who I think is really a nice person. I pondered how it was possible and this is my theory - it might be scarier for them to accept that a tragedy could be random and unexplainable. There is really no way to completely defend against that. So when somebody with an agenda offers an "eplanantion" some people grab onto it, not becasue they are mean or hateful but because it takes away some of the uncertainty.
I certainly will correct those things if I have evidence that they are false but I try to figure out motivation. For some people it is makice and anger, for others it is genuine fear.