I find it amazing that it's so common to think so lowly of anyone who believes vaccines cause autism. There's nothing inherently ridiculous about this idea, there's no reason it should be impossible, and there's no malice in such an idea. And there are good reasons to think it does if you do some research and think for yourself. I think the most obvious reason people feel that way is that they have a bias toward wanting to believe that vaccines are an infallible godsend, which stems from the fact that society has a collective form of PTSD as a result of past diseases.