My two cents: if an airbase's fuel tanks are all gone, no flight ops. Simple Boolean logic.
Except that sometimes the tank farms are some distance away from the field, prevailing winds might be favourable for continued flight ops, invisible civilian assets may be available to fight the fires and blah, blah, blah.
There are too many potential variables at work here and no way for the developers to please everybody. The current situation is not broken so it hardly needs a fix, Boolean or otherwise.
The reason I suggested that approach is that the game essentially does that for ammo. If all the ammo storage sites are gone, the planes will not re-arm.
There are a lot of potential variables at work there too, but everyone seems satisfied that blowing up all the ammo storage sites has tangible effect on flight operations.