I don't understand why suddenly people think vaccines cause diseases like autism. Many medical experts have said otherwise.
Because big pharma totes paid off the medical experts, dude! Wake up sheeple!
Or, put more bluntly, because people are idiots
I wouldn't go so far as to say "people are idiots" as the reason. I think the two biggest components of anti-vaxxerism is that autism tends to become diagnosable around the same time kids start to get most of their vaccines. It's only human to notice patterns where their are none. Second is that people who are model parents in every way suddenly have a kid who is autistic. The natural reaction is to think "but I've been a good parent, fed them, clothed them, loved them, got them all of their shots, this must be someone else's fault!"
Modern Americans live such high-quality lives (by historical standards) that we have a great deal of difficulty coming to terms with the awful randomness of life.
So many people make things up instead of acknowledging reality. They do this in very focused ways, as with anti-vaxxers. And they do it in huge, sweeping generalizations, like the GOP's pernicious Prosperity Gospel. (It comes in both secular and religious versions.)
