AZ, in addition to hunters education, has a ethics course.To some degree don't game laws serve this purpose? No more punt guns for waterfowl, spotlighting/killing deer at night is illegal, there's bag limits for any given critter, well-defined methods of taking game, established season length and on and on. To me, hunting regs are the State's way of serving as the gatekeeper you mention.
Fly fish for trout? Great. Zebco 33 Classic with a red/white bobber and mealworms? That works too. I don't see any unfair advantage with either of these options...not so with those mentioned above.
My day job requires a license and part of that is a required ethics course every two years. I'm of the opinion that you either have ethics or not. Sure, some of us can be taught a thing or two but at the end of the day you either got em or not. So, I think it's ok for hunters to hold fellow hunters to higher degree. We shouldn't be extreme with it but we shouldn't turn a blind eye to it either.