A well crafted spear is indeed art - since it doesn't absolutely need to be well crafted, it is that aspect of the spear-as-tool, specifically, that is consider

A well crafted spear is indeed art - since it doesn't absolutely need to be well crafted, it is that aspect of the spear-as-tool, specifically, that is considered art, and elevates it to that realm. This is why OP said the argument is flawed, because it is. It becomes highly subjective quite fast. But thats the reasoning.