One of your next questions will probably be, why did they choose the Bf over the Fw?
The answer is that the Luftwaffe and it's leader(Goering, lol almost said Goebbels) were friggin prats(well... Goering was anyway...) and wanted to limit Germany's naval airpower so he could maintain full and complete control over the Luftwaffe and all air-related going-on's. Thanks to his political maneuvering, he managed to delay the production of the Graf Zeppelin for years(and forced the second Carrier to be scrapped early on due to his delay tactics), and when he finally compromised, he agreed to allow the production/conversion of old useless obsolete aircraft into naval versions. In addition, he would maintain complete control over the naval air service.
In fact Graf Zeppelin was about 95% complete at the end of the war, it would have been completed if it weren't for him.
Entirely pointless but I had a rough day and need to make myself sound smart.