Plus ça change, plus c'est la même chose.
Before leaving around 13 years ago, my Master's thesis was on RAF FJ pilot retention. After a fair bit of research, a pattern emerged that most pilots were hacked-off by their early thirties and left as soon as possible after that point. (An obvious exception were the hard-core career guys who loved the service truly, madly, deeply.) This correlated broadly with when family commitments were ramping up: concerns about time away from small children both day-to-day as well as on the many routine deployments, and more concerns about money generally. At this age a more mature assessment of the likely benefits of the civil sector seemed to come into play. Compare this to the first-tourist who would probably take minimum wage and/or beer money for the pleasure of throwing one of HM's pointy jets around.
I think, therefore, most decisions to leave are taken when the declining ‘fun’ line crosses the rising ‘need for more money’ line on the graph. If the RAF/MoD/Treasury could delay when the money issue becomes critical, I suspect many individuals would stay a bit longer. Even one extra productive tour per pilot would result in a massive cost reduction through reduced numbers in the training system. Only a small element of that saving would be needed to pay for a more substantial retention package for those with the highest replacement cost.