Apple doesn't refer a sale. Apple makes the sale. They are the store, something they have set up and enforced.
The developer has no capacity to deny a customer, yet has the responsibility for the bad customers shopping someone else's store.
The developer has no capacity to deny a customer, yet has the responsibility for the bad customers shopping someone else's store.
The ethics of this scheme are debatable but it should be assumed that some refunds are legitimate and Apple loses tangible customer $LTV from some refunds.