I'm totally with dash2 here.
When I was a brand new pilot I would gladly have worked for far less than a Fg Off gets paid - and getting flying pay was just a bonus! During the first few years of an officer's career, the pay and conditions compare favourably with other professions - long hours, unpaid internships,donkey work and cut-throat competition are all very common for new graduates seeking to climb onto the corporate ladder.
Later on, though, the pay doesn't reflect the increase in workload and responsibility, in my opinion. But people leaving to start a second career don't just do it for the money - some are looking to reclaim some family time, some have had enough of moving around every 3 years and want to put down roots, some just want to try something different in life.
Flying pay isn't tied to the health of the airline job market. Much more important is the cost to MoD of training aircrew (hence why WSOs and WSOps get flying pay as well). It doesn't matter what civvy careers aircrew go to - the point of flying pay is to encourage them to stay and maximise the value obtained from the expensive training. More experienced aircrew get more flying pay as they have built up a large pool of experience at even greater expense - it's even more in the MoD's interest to hang onto us.