I've been watching this for years. I've come to believe what you say is true. The goal is for rich coastal elites (San Fransicko, Hollywood, Silicon Valley and other wealthy liberal enclaves to run off the bothersome "little people." They want to enjoy the state's unique climate and beauties for themselves and use cheap labor from Mexico.
When $15 becomes the floor, don’t be surprised if it ends up being a hard ceiling that employees will have a hard time breaking through.