Some parents (especially low income and uneducated) believe with their whole chest that vaccines are worse than the disease.
They think they're smarter than doctors and everything is a big conspiracy theory. They will believe anything if you put it in a chart or make it sound official with a statistic.
I think a lot of them suffer from some type of underlying mental health condition.
I knew a few and they weren't the brightest bulbs. One sold me a tablet that needed a "new battery" because I bought and sold broken electronics at the time. All it needed was a charger

I got a $300 tablet for $40 assuming that I needed to change the battery on it.
All it needed was a charging cord that wasn't broken.
This person is making medical decisions for a human being.
A person that couldn't figure out their cord was broken, is making actual life changing decisions for a small child.
People like this vote. The same people that can't figure out their computer is unplugged or that they didn't push the power button before calling technical support.