UL, why are you expecting your family to think as you do? They don't. Accept it. They have that right.

You have the right to responsibly deal with the result. People love gadgets so give it to a sports organization that can use it as a fundraiser or door prize. You can tell dad that the sports group needed the money to help save fish or aid youth or whatever and it seemed more valuable to use it that way than occasionally using it to fish.