As far as I'm concerned, the point of having a survey, is to let everyone have a chance to put their opinion. Even no-voters, shock horror
Did you vote on the union's proposal? And by that, I don't mean the ballot, but the (IMO) outrageous proposal with the cost savings which pwc proved to be untrue.
When a union represents (in this instance) thousands of members, it is important to ask the members what they think. Yes, there would've been lots of different opinions, but it would've given the union a good indication as to what the members wanted. Then it's fairly easy to go ahead with the most popular suggestions.
Simple, really, when one thinks about it.
Gg