OK on reflection maybe the "stupid" theory does fit the facts pretty well. Still, I think that for every evangelical antivaxxer, there are a fair few people who are just like "As a parent I have the right to do what I think is best for my own child [and I don't give a fuck about yours]".
"I think the risk that my child might get polio and develop horrific, crippling, and permanent physical disorders that will make the rest of their life a struggle is acceptable given how horrible autism is!"
Ask someone older than 70 what polio is like. They all have stories of someone they know being struck down by it, and even those that squeaked through and survived never did well.
