Except you know... they won't be the same state anymore. It won't be too many years before they act like six competing states because of competing interests.

By staying one state, California has the benefit of being one of the most powerful economies on the planet which, even without having things pass at the federal government, allows significant world power.

California's car efficiency standards over the years for instance basically forced every car company that sells a car in the US to up their efficiency. There is no chance that would happen if it was just 1/6th of California.