I've lived in Vegas (80s) and SoCal (90s/00s) and got married in Vegas over 10 yrs ago.
I can agree with almost everything posted in this thread. The reason ex-pat Californian's have so much money is because of real estate prices and gov't ponzi-scheme pensions. Starting with Jerry Brown's (70s) administration the state made it harder to get building permits. The housing shortage drove up prices. The shortage was due to people fleeing the rust belt and Cali welcoming millions from south of the border as well as many other places.
A house that sold for 80k in 1975 now sells for over 2 million. Also, state/county/city employees fully vested have insane retirement packages. Some of them double & triple dip. When they retire, they sell their homes for millions and take those pensions to a state where 2 mil buys you a mansion instead of a Caleftornia middle class home.
Who buys those modest houses for 2 million? Corporations/individuals whose business model is partly (and sometimes exclusively) rental homes. Many of those rentals become clown houses. Single family homes end up being occupied by 15 people or more. I saw it first-hand in Calabasas; Sun Valley; Manhattan Beach; Mar Vista; Newport Beach; North Hollywood and Anaheim. And it was reported on the John and Ken show (AM radio) continually for many years. Plenty of others covered it as well.