You would do well to learn that in a democratic, free society, the right of a person to strike is one of the most basic ones... Iberia employees have a fundamental and undeniable right to strike for as long as they want. I understand that for a Briton the rhetoric might be slightly unfamiliar and grossly offensive, but that is how business is done in different areas of the world. If, in the UK, we had unions that were slightly stronger, perhaps the distribution of wealth would be different, and the class-hierarchy would be long dead. As it stands, it is little wonder that certain (very large) segments of the population view 'middle-class' as a disdainful term...
I say this (in the interest of full disclosure) as a person who is flying IB in two days, and was scared of this strike ruining my plans.