The profit sharing was agreed to by the East MEC reps long BEFORE the NIC even came out. It was the unanimous decision at the time, and correct in retrospect even now.
Viewing it purely through the lens of tactical advantage/disadvantage; it was clearly a foolish gesture, but if one truly believes in unionist principles of any kind, then it must be seen, even in retrospect, as the right thing to do. All of a same class and craft should be treated with equal respect within any supposed union, or else you have nothing worthy of that name.