The weather and the people. SoCal has a climate in which being broke and begging is tolerable, if you notice, many of the cults accentuate poverty as a lifestyle. The population is also a more receptive audience, much of the population moved there to live their life on their terms and experiments are common. This population also has the double whammy of not only being more receptive, but also unmoored from their community and it's an easy way to find friends. Many cult experts will tell you that not having access to strong family or friends support is a risk factor when dealing with cults.