Of course they're committed to the franchise (for now) because it gives them huge benefits with little financial risk, and ties in with it's strategy of offering a high frequency product so that it can segment its market and tailor its product as such, with the added benefit of increasing connecting traffic.
I was just making the point that for Aer Arann, having all its eggs in the one basket poses a huge risk should Aer Lingus decide in 5 years time it wants to change its business model. It was only 10 years ago that Aer Lingus Commuter was wound up because it wasn't part of the airline's future strategy.
If you want another example of what could happen in 5 years just look at CityJet now which wasn't included as part of Air France's recent future regional brand strategy, which has put a large question mark over it's future in the group and any sell off could mean large job losses.
Just my 2c. Ar aon nós, moving on...