Why six-inch guns seemed rational to German designers

Did the Kriegsmarine's shortage of cruisers justify Graf Zeppelin's six-inch guns?

It helps explain why designers wanted self-defense guns, but it does not rescue their low, poorly arranged casemate installation.

The comment reconstructs the design logic sympathetically: unlike a Royal Navy carrier likely to have a cruiser escort, Graf Zeppelin could not assume a suitable ship would always ride shotgun. A shortage of German cruisers made organic surface-defense weapons seem like insurance against an escort gap. The reply accepts that institutional and force-structure logic as a partial explanation. The low casemate arrangement and restricted arcs still made the chosen solution ineffective.