>Why dont we call leather what it is - chemically treated skin Because that's literally the definition of leather: "a material made from the skin of an animal

>Why dont we call leather what it is - chemically treated skin Because that's literally the definition of leather: "a material made from the skin of an animal by tanning or a similar process." You may as well argue we should call headphones "a pair of earphones joined by a band placed over the head, for listening to audio signals such as music or speech."