IMO, one of Cork's biggest problems is Corkonians flying from Dublin on routes already served from Cork. But how do you stop this? Only way is to make Cork cheaper than Dublin. The DAA won't care about this because they are still getting their money regardless, and pax will prob spend more money in DUB because of the larger selection of shops, plus the handling fees in DUB are bound to be higher. EI and FR won't care because you are still on their aircraft. Government will prefer it because you are probably doing a bit of shopping in Dublin and maybe staying in a hotel, so more tax for them.
Only way to stop that would be for Cork to be made independent like SNN, but ORK would have to take the debt from the new terminal with them, and would be on their own to sink or swim against a debt free Kerry and Shannon, not sure if they could do that.