Conversely, on its own, the fact that they remove some ambiguities is not a sufficient reason to use them. Since the downvoters disagree, I'll provide a proof.

Conversely, on its own, the fact that they remove some ambiguities is not a sufficient reason to use them. Since the downvoters disagree, I'll provide a proof. 1. Suppose resolution of ambiguities is a sufficient reason for a separate case in written language. 2. Ambiguities exist that are not resolved. 3. New cases are not created to resolve these. 4. By contradiction, 1 is false. QED There may be other reasons which in addition to the resolution of ambiguity are sufficient to justify case, but you can't simply cite the resolution of ambiguity and say conclude that case is justified.