The difference being, there's not much use for your heart once you're dead. Not only that, but it's useless even for your family, since they can't simply sell

The difference being, there's not much use for your heart once you're dead. Not only that, but it's useless even for your family, since they can't simply sell it or profit in any way as they would with most things (unless you're also advocating for the family right to sell your organs).