A couple of points.
Firstly, to those (such as 'homerj' above). ATC is, indeed, a modern form of 'the public service'. ATCOs don't receive large performence bonuses, profit share, or any other such benefit. The flipside/upside of that is; they get their salary week in, week out. They don't get a large whack when times are good. They do receive small, negotiated, periodic percentile increases (regardless of what is happening in the wider economy, and regardless of how anyone feels about that- this point alone could require it's own thread).
What is so hard to understand about that?
On the other hand, ANSPs are often managed by individuals whose remuneration has a large component derived from performence driven elements. These people will do anything, ANYTHING to obtain said payment. This includes ignoring/disregarding said agreements with said ATCOs. It includes cost-shifting to airlines (something that I am constantly amazed the airlines either don't understand, or wear without qualm). It includes, shall we say, 'pushing the envelope' regarding safety in manning levels etc. Unfortunately, often the only way ATCOs can 'push back' is with industrial action.
So, to all those crapping on about the wisdom or lack thereof about IA, ask yourself this: if the manager's bonuses suffered when IA disrupted services, do you think it would ever happen?
Put the blame where it belongs. The union doesnt pick the fights. It just fights them.