Problem is, when the majority of your staff go on strike you can't just sack them all, paricularly ones such as the engineers at Aer Lingus where Aerospace Engineers are already in extremely high demand, you'll have lost them to other companies with in no time, and it'll take years to train in new ones, as with cabin crew you're talking about upwards of 10 weeks to train them, much longer in fact, as you'll no longer have the people who are trained to train them on your pay-roll. So in practice, that doesn't work. No airline can survive for 3-4 years without operating flights while they train in new staff.
So you reckon that an airline couldn't find Pilots, Engineers, Cabin Crew quickly ?
An airline with a fleet the size of EI could dismiss all its staff and be flying again with 14 days maximum using contract staff brought in from everywhere at what ever cost is necessary.
Politically it would never happen in Ireland but never assume management would not go for the nuclear option........................that one has been proven by many Unions to be a bluff called and actioned.