The climate may be too cold/cool and moist for middle Eastern Saudis.
When the Shah was disposed, many Persians fled to the bay area and opened up small businesses. Some are still open and some are being run/managed by their adult children and grandkids. They and their off spring are good people and citizens and hate the Islamic thugs in charge of Iran, now.
I find it interesting that they rather be called as Persians, rather than as Iranians.