Why is this 70 year old guy so obsessed with something he knows nothing about? Why name Tylenol the “cause” of autism when he obviously wants to say its vaccines?

I get that the underlying goal of MAHA is eugenics, but I just don’t get why or this angle. I haven’t come across much really talking about it. Everything is focused on the fact that its obviously ridiculous that Tylenol (or anything) causes autism, but what is the obession with finding this nonexistent cause?