Ha ha - you know the answer to that. The saviour Sheens in 2012 sacrificed Wests by placing all NRL players with Balmain Ryde Eastwood. Wests got hammered most games and ran last without a win in the season. It was decided that seeing Wests were shit and to avoid funding of 2 clubs they would combine BRE and Wsts and play under the Wests Tigers banner. Didn't sit well with either Wests or BRE who had made the grand final in 2012. By 2017 Balmain were broke and financially contributing absolutely nothing to either the NRL or Cup side. I have no idea why, but guess it was because of financial reasons the NSW cup reverted back to Wests Magpies.
I don't necessarily agree with the decision but i can see the reasoning behind it. Unfortunately we have been a pretty fractured club from day 1.