It is dumb to make a blanket statement about "California" as enforcement varies greatly by area as does the attitudes of law enforcement. It is like saying French policemen do whatever as a generalization. There is always some LEO that wants to pad their tickets, especially at the end of the month, to make their informal quota. I am happy that in much of California we do not have street executions by cops.
I appreciate that for motorists to respect the rights of bicyclists to share the road the bicyclists should observe the traffic laws in the same manner as people in cars are expected to do.