I personally know very intelligent and highly educated people who went to top universities who are convinced vaccines caused mental retardation in their children. They may be wrong, but I would not call them nutjobs.
Imagine trusting a "rocket scientist" to even weigh in on medical topics because they are "very intelligent" in their totally unrelated field. This is an unfortunate misconception that plagues conspiracy theory extremists who reference PhD graduates in their arguments against things like 5G brain control.... pointing to people with doctoral degrees in Music or something.
However, as the saying goes, science advances one funeral at a time.