Sure, but in the case of an open-source developer working on macOS, he has already paid for his operating system; if he is using GCC, he has already paid everything the GCC developers require; why then must he pay extra money to Apple in order for other people to run his software in a straightforward manner on their machines (or, in the future, at all)? How is Apple even a party when two people wish to transact, when one writes and compiles free software on his hardware (paid for) and software (paid for) and the other runs it on his hardware (paid for) and software (paid for)?