Given the lore and the limitations the current inhabitants have with respect to manufacturing, I feel relatively satisfied if you play the 'Arms Control' card with respect to fighters. It makes sense to have all losses and repairs cost 'supplies' though, perhaps balancing slightly against that pesky single wasp that always seems to get away ...
My take on the 'Arms Control' explanation:
A fighter wing is manufactured using a blueprint at an Auto-Factory somewhere, and the technology that goes in to all this assigns each wing with a unique reference number.
The technology that is present on a carrier flight deck can recreate a wing in accordance with the specification of that reference number, maintained in a database conceived many years ago intended to control and regulate the production and proliferation of arms. This database could be shared between all fighter producing technologies, either transparent to the factory operator or perhaps long forgotten about after the machinery specification was first set up.
The more limited 'repair-bays' aboard carrier flight decks can only reproduce fighters and bombers if they have this 'regulation' data (from the original manufacture process) to work with (i.e. the signature from at least one ship). If this wasn't the case, these carrier bays could, in theory, endlessly pump out fighters and bombers, which would be a serious threat in the wrong hands, and a concern for a weapons regulator.
Maintaining a set number of full wings (for defence purposes only), on the other hand, would be fine, and would be the kind of thing that an arms regulator might have originally be happy with when the equipment was designed.
And of course nowadays, no-one really knows how these things work anymore, so they are at a loss to change them from the original specification. They work how they work, despite it being a bit strange in a warfare situation.