In my understanding, only implicit accounts can initiate a transaction. Then, if I am correct, the destination of SOURCE must be an implicit account, and the question arises.
I know various ways to convert a value between key_hash and address. So, this is not a critical issue. I am just wondering or thinking it would be nice if SOURCE returned key_hash. For example, we can use IMPLICIT_ACCOUNT and avoid ASSERT_SOME check.
Is there any reason, or the my understanding wrong?