I'm not so sure that the airlines are making financial contributions to Resort Airline Check-in. BAGS Inc. (the provider of Disney's Resort Airline Check-in) also offers remote airline check-in services at some conventions and some hotels, with the passenger paying the fee for the service. But, even with the passenger paying the fee, the service is limited to participating airlines. I think it's more likely a matter that some airlines don't want an outside company accessing their systems, or that there are unresolved system compatibility issues. I think Disney is paying BAGS Inc. to provide Resort Airline Check-in.