Robert Reich points to teachers moonlighting as Uber drivers in Silicon Valley as an example of the perverse logic of this area. There is a perverse logic here--companies like Facebook and Google serve vast number of customers with relatively few employees, making a few rich but leaving most out--but that's not what's happening with teachers. There is no logic to that. There is a combination of overwhelming economic forces and terrible laws.
The current round of high-tech companies has been so successful that they've outgrown both the local housing market and the infrastructure that supports it. Facebook, Google, Apple, Salesforce, et al continue to be successful, continue to grow, and continue to hire. Their employees continue to look for places to live. There's only so much room. There are only so many roads, schools, parks, and teachers.
Because of Prop 13 and its descendants, there's only so much money to pay for public services and employees. Property taxes are capped. Other local taxes are nearly impossible to raise. Neither the state nor the federal government are likely to come to the aid of the country's richest areas.