Most cars that are stolen had been left unlocked (i.e. the owner did not follow best practices). Should victims of car theft pay for all policing related to auto theft?

Regardless of your answer to that question, you should remember that law enforcement are not there to serve and protect the people, LE are there to serve and protect the system (society and government). Many law enforcement agencies have been sued for failing to protect the citizenry, and their defense is usually that they have no duty to do so.