They don't know
I don't think that you know that their decisions are demoralising their staff, I guess they just don't realise the long term effect!
Some one have to show them the large numbers of captains f/o's and trainers leaving the airline, this is an expensive process (against the saving of the MFF concept).
Unless like Max said:" the plan is to piss off the instructors, so the friends from home can join QR as direct entry instructors" well....maybe that is why they said: we don't care about the seniority any more...any fleet transfer is going to be by selection and merit?