One I remember going to often was Louisiana Hots, in Palmdale. One of the local hotspots, their Friday Karaoke was hugely popular, and seeing somebody come in like Jamie Jones (All-4-One), Noah Hathaway (Boxy, Atrayu) and Afroman were regular occurrences on Friday night. But when the ban went into effect, the business basically crashed. They tried to put in outside smoking areas, but the county said each was in violation of some kind of ordinance, so eventually you would go there and see 100 people in the parking lot, but nobody inside.
A year later they closed their doors. I talked to the owner right before that happened, and he said the 100% smoking ban killed him. And several other places I went to suffered the same fate. In most of California other ordinances restrict or prohibit outside seating which allow smoking, so the only choice is to leave the business. The most recent prohibits smoking within 20 feet of a door or window, which outlawed most of the patios which allowed smoking, since I have never seen one 20 feet from a doorway.