Given the fact that Emirates will need somewhere in the region of 700 Captains between now and 2018, provided there are no further delays or cancelations of aircraft orders. Also provided there are NO more DEC's (yeah right).
If NO more F/O's were hired between now and 2018, there would still be 4-500 F/O's who are on the current seniority list waiting for upgrade to Captain in roughly 10 years from now.
Based on these numbers, any F/O joining EK now will likely be waiting 15 years. 15 years based on the company expanding as planned and no further world economic crisis, flu pandemic, terrorism, war etc, etc.
With all of the current contract and COS degradations the package is no longer good enough to spend this amount of time in the right seat living in a third/fourth world country.
The biggest drawcard of Emirates has, and will always be a "first officer fast tracking his career". Another drawcard which no longer exists.
There are other opportunities around.