Problem is that many who are moving aren't giving a whole lot of thought as to why California has had such a large reduction in quality of life. They simply know QoL has declined to a level where they want to be somewhere else. They may have different theories as to why QoL tanked, some might even know that some of the policies they voted for had a hand in it while believing that they simply weren't implemented well in California but think "we'll get it right this time" in their new home state.
Quality of life in California is grand if you don’t factor in the high cost of living, which is primarily due to land being expensive. California is a victim of its own success and of its bad zoning laws and nimbyism.