Airports should supply wheelchairs, crutches and maybe even pushchairs for those passengers who put their means of getting themselves or others about into their checked luggage. At airports, at least in the US, it is not the airline that supplies the wheelchair, it is the airport - thus, Sensible, the cost of the wheelchair is paid by the airport, and once spread over all the airlines that use the wheelchairs (etc) the cost is incredibly low per chair. Long and short: Ryanair should have nothing to do with the supply of wheelchairs etc, it's the airport's responsibility.