Of course legacy staff want to protect their T&Cs - who wants to be paid less for the work that they do?! Their wage reflects the market rate as they expected when they started their employment and progressed, and I imagine very few people expect that they will actually be paid less as their career progresses. Indeed the proposals made will be ruinous to some.
​​​​​
It is the job of their union to protect those T&Cs. There are a number of unfairnesses in the job market that seem to fall solely on newer entrants (no final salary pensions and higher employee contributions for example) and are apparently otherwise accepted, so I don't think mixed fleet or easyJet being paid less than legacy BA staff is much of an excuse here. You can argue that the staff are overpaid in comparison, but they are being paid what they were offered when they began their employment in the same way everyone else who takes a job will be, in line with the expectations the employer sets. Indeed, one could also argue that Mixed Fleet are underpaid in comparison.

BA will unfortunately have to make redundancies in the current situation. However I find it hard to believe that also forcing everyone onto one contract is the difference between it going bust and surviving this.
​​​​​​