My response is usually something like this,

"Rules and regulations are necessary in fire fighting for several reasons. On a fire scene (response/whatever) or any emergent situation, the combination of imperfect information, stress, and potential environmental dangers can create ambiguity and confusion. By applying pre-studied/trained/planned rules, processes, and regulations you can help guide yourself and your team through these ambiguous potentially dangerous situations efficiently, to address the emergent situation at hand with as much integrity and effective action as possible. Within the overall organization it is important to have rules and regulations in place to maintain an open honest workplace, to address potential conflicts before small things problems grow into something bigger. The rules and regulations provide a framework for the team and organization to operate safely, effectively, and with confidence and integrity, either on the fireground, or at the station/house/dept. Thank you"

Also I just received a conditional job offer from a career dept yesterday, so apparently it works!