So, actually you really need a more mature point, one which is reality in a real world. I don't need insurance to go take a crap, even though sometimes I use someone else's crapper. OTOH if you fly RC on MY property you will have an AMA card. That's the way life is.

The rifle range is a business and provides you a place to do what you do there in return for a fee. That is what all business is -- providing something for something in exchange. AMA provides you some additional financial well-being for a fee, and likewise, most clubs provide some financial security for their members by requiring that each member has the AMA program, thus each member has the wherewithal to take care of any damage he might inflict and at the same time be protected against damage his fellow club members might inflict. That reasoning parallels why many states require drivers to carry commercial public-liability insurance.

Now you can bet your sweet patootie that the rifle range has adequate insurance to cover itself against both its own liabilities as well as yours. The difference is that the rifle range doesn't give a tinker's-dam about what happens to YOU. The rifle range may well take everything you have and ever hope to have if you perform a careless action while on their property which severely damages someone's person.