Coming from born in the bay area and fairly deep roots on the west coast.

The post war boom years are a fertile time for cults in California. You had a lot of people who were isolated from their previous communities that were often easy marks for grifter run cults of all sorts. And not just California. But probably less visible in the Midwest with a less dynamic and conservative population.

Also: My definition of a cult is the question what happens when you try to leave?