Religion
Marin County, which is not a hot bed of any religion other than yoga pants, EV, soylent drinks etc, is the largest population of anti-vaxxers in California.
https://www.google.com/url?sa=t&source=web&rct=j&url=https:/...
Also seeing right through some unscientific nonsense does not protect you from all of it.
There are people who laugh at Creationism and then turn around and deny Anthropogenic Global Warming. Others laugh at both creationists and AGW denialists, and then tout Health At Every Size. And there are people who reject vaccines despite being perfectly able to accept scientific evidence in the other mentioned areas.