The 1% in California has never been that concerned about the high price of housing. They can afford it.
If they really cared (e.g. they perceived it hurt their business) they would have used market mechanisms and moved their business out.
What makes the SB50 result predictable is that ordinary homeowners benefit from the situation. (e.g. they can someday rent out or sell their house at an inflated price while paying low property taxes.) Homeowners vote more than renters, and importantly, the people who might move to CA if housing were more available don't vote.
Another way of thinking about it is that CA is crazy crowded anyway. I'm thinking of a neighborhood in Santa Monica where people live in pretty little single family homes with pretty little yards, well tended gardens.
In a place like that, people are very affected by what their neighbors are doing and they don't want more.
CA's style of development is also expensive economically and environmentally. If you do build more housing, it will need more infrastructure, and at American rates for building infrastructure it is hard to come out ahead.