The left uses that because it’s true. And it’s a valid counter argument. Which is why this is a weak argument despite your analogy. Could be inordinate amounts of refined foods? Lack of exercise? Shitty family life because No dad? Or maybe the definition of “autism “ has become so ridiculously broad in order to sell drugs to “treat” it? Think critically. Yes it could be all due to vaccines or partially or several things. Or none of the above.