I'd worry a bit about the reliance on airports which have runways too short for Ryanair to use them.
With improvements to the road network, other airports are not as inconvenient. When the Gort bypass is completed, Galway will be all of 45 minutes from Shannon. Sligo is already about 40 minutes from Knock, before any improvements come on stream.
Both those airports are probably facing up to a future of extending the runway or closing the airport. If they extend the runway, Ryanair can come in, if they close, it's no good to Aer Arann.