Yeah otherwise laws don't mean anything, right? It's free-for-all. From "stopping at a Red light is optional" to Vigilanteism. Can you explain how that would work? Would you want to live in that kind of state?
A) You are born into a system without your permission, and must abide by the rules of those in power or you will be punished.
B) Laws can also be morally sound and in place for good reason.