Yes, the public is a customer of the criminal justice system as it is the duty of the criminial justice system to serve the public. The criminal justice system must do its best to ensure that the needs of the public are met, in a way, much life a server in a restaurant.
Asking if the public is a consume of the criminal justice system is a unique questions I would have to say I agree with. As I see it in my small town, where the criminal justice system is more visable on a daily basis, criminals are often forced into paying for services they would otherwise not use unless ordered by the court. This includes probation services, drug rehab services, and defensive driving services.