I seem to remember Mr. Ripley being a brother from across the pond. If that's the case, there's no wonder he's taking this completely out of context and shocked at the inappropriateness.
Advertisements in gun magazines and websites regularly look like this. They are fundamentally no different than if they said, "Don't Tread On Me", or "For Things That Go Bump In The Night". It's not meant to give direction, it's meant to be kinda catchy and make the reader say, "Haha... yeah. That's cool" and consider the product. Anyone looking at that poem with small children at home who thinks "I can leave my Glock loaded, chambered, and easily accessible to anyone in my house because the ad for the zombie paint said so" is a certified idiot who is only around because mankind has refused to let natural selection take it's course.
Hope that helps.