Just because EK has always hired DECs does not make it right now. As recently as 8 months ago the company said they have no plans to hire DECs as they were a mistake and a huge headache for the company not to mention shafting the FOs. Hence many well qualified FOs joined thinking no one would jump them. Now we have this.
No matter you point of view most even keeled pilots would agree Emirates does not need DECs at this point. As was said above the classes are full, just upgrade the well qualified FOs already here.