This is pretty interesting. However the idea of guns a a symbol seems like it would apply to groups that are organized around gun control, or the prevention of gun violence just as much as it does to those who value guns. Those surely have to count as ‘gun cults’ by the same reasoning - they just regard the gun as a negative symbol rather than a positive one.
That's an interesting thought and one I hadn't thought of. I think the author would agree with you too given how he (briefly) describes the animal rights movement.