Right now there's around soixante trois F/Os who have been at EK for close to or over four years. Some of them have medium jet command time with major carriers. All of them were experienced crew at their time of joining EK.
Pre DEC program most of them would have expected a command opportunity at EK at around three years and they joined with that expectation.
The DEC program was created as a stop-gap in late 2003 to crew the sudden arrival of the ex Singapore Airlines 340s. EK realized how cheap the DECs are and they're still recruiting them.
The result is that EK now gets plenty of DEC applicants (although many fail the selection process) but no longer gets the quality of F/O applicants in the quantity that it needs because it is well known that progression from right to left seat at EK has become a lottery.
So who wins? Not the F/Os for sure. Cost-wise maybe the company, for the moment anyway. The DECs win but at the expense of the command salaries and seniority of the four years and counting F/Os.
No surprise that a lot of the bad press that EK gets on this forum is a direct consequence of the DEC program. Go figure.