BALPA struggle to get even a 1-2% payrise for their members and even then its at the loss of other benefits, usually starting with those of the F/O's. Pilot unions are pretty toothless really and to expect them to be able to put an end to this P2F situation is not realistic at all.
I disagree. We've just had a 4% pay-rise and a share scheme (worth approx a further 2.5%) negotiated (amicably) by BALPA. Granted, we did take a cut a couple of years ago to prevent redundancies, and we also have RPI to consider, but it's still a very good deal.
Keep in mind that the 1-2% pay-rise you mention, for the entire pilot workforce, will cost a company much, much more than any lost revenue from scrapping a P2F scheme. A realistic, intelligent union can be quite strong, I think a lack of interest from current pilots is a bigger problem.