Two issues. (1) Nature editors desk reject most papers without review, so editors should be blinded to author identity as well for this to sort of work. (2) By

Two issues. (1) Nature editors desk reject most papers without review, so editors should be blinded to author identity as well for this to sort of work. (2) By still allowing single-blind review, it gives the reviewers the notion that the authors want to be anonymous because they are not famous scientists, because a renown scientist with lots of Science/Nature papers would probably choose single-blind.