Monopoly
This is quite annoying actually, but it's not the fault of the Airline.
Apple's interface is propriatory, but there should be a standard interconnect/dock system for all personal media players. The control mechanism should be open and usable by other manufacturers, like IRivier, Samsung thingies, even Zune (not that they would use it!).
As public places adopt more proprietary interconnect, the monopolies people will start to get more interested in this particular marketing channel... and it wont always be Apple's fault, rather public demand. So how to solve this other than asking Apple nicely if every man+dog can use their interconnect design and control protocol?