Perhaps another relevant factor is that the serious numbers in hiring started in 2006-2007.
The first bunch are now coming to the 7 year itch (fully vested in Provident Fund) and have had enough - particularly the NWA/DAL DECs & and the Ozzie
VB FOs. Not to mention some other nationalities, who have lets ets face it, never been made welcome (and English is our mother tongue! Yegads if you had an accent in 2006)
So now they and many others are free and clear to move on, and as Typhoon said - they will.
So the happiness you see in Costa HQ as the EK HR crew sip espresso (they all seem to spend a lot of time there smiling at each other) may start to wilt a little as the experience exits but the questions amongst them will never be: "Why did they leave?" But rather "what's up with them"
The answer; don't know... Your advertizing?
f.