The problem for the guys and gals that have been at FR for quite some time is that the T&C's are being constantly eroded. Someone who is a skipper might be on say EUR100k (figures plucked from the sky but probably not far off for someone in under 10 years). It probably sounds a lot. But remember that each year they give you a pay rise with the one hand and then deduct a bit for this or a bit for that or change the rostering system so you are working longer.
The problem arises when you stay in TOO long. Each of us typically spends up to our own means. We take out mortgages up to the limit of our means so that we can live in a better area. So whilst they might want to jump ship going to a legacy carrier where you might be on 50k as an f/o is a hard pill to swallow. Yes they will get their pension, sector pay, uniforms, carparking, meals, union recognition, seniority list, hotels etc etc but they still have to pay the mortgage at the end of the day.
The moral of the story is leave early or don't go there in the first place. History has shown that membership of IALPA/BALPA will get you very little as management have no willingness whatsoever to come to the negotiating table despite the best interests of many of the pilot fraternity.