That's a massive oversimplification and to be honest a union cop out.. If it is a majority YES then it is implemented. If it is a majority NO, back to the table it goes.
As I've said before, many who vote YES only look at the percentage pay increase and back pay, not the claw back small print. THAT, along with those who can't even be bothered to vote, are a big part of the problem.
These negotiations take a long time.
Once the PEC endorses a deal it is recommended that it is accepted and the majority of branches will fall into line and recommend it.
There are then reps meeting where they are pushed to recommend it to the members.
It is in most cases made clear to the members that there is no plan b for negotiation and this is as good as it gets.
With this backdrop you expect the membership to do anything but accept a deal?
It's not about back pay or small print or even those who can't be bothered to vote. The only people who could ultimately influence a vote once it has been endorsed by the PEC are the Divisional Reps with support of the Branches (Some have more influence than others).
It is about how the deal is sold to the members as the only deal in town. That's why the members accept those deals.