Goblins are the bankers of Gringotts bank. But they are mistreated. We deny them the use of wands, and we do not respect their preferences. Goblins see Goblin-made items rightfully theirs, and they consider the witch or wizard who bought it, as the temporary renter. But we pass the goblin-made items down, without repaying the Goblins. They consider it little-more than theft. Remember that when you inherit or buy Goblin-made items. Even Godric Gryffindor didn't respect their ways. He never made sure that his sword passed back into their hands after he died.