Hey, don't balme the DECs too much here. They were after all just other guys out there looking for another job. EK recruited them and now they are here. Those that make no effort to blend into the culture (of complete negativity) are a problem but surely there must be a few that have managed to fit in and make life better for all.
The management is to blame for getting the airline into this situation of low morale. Perhaps if you accepted as many of the DECs as possible into the group life would be better. After all they were only seeking new employment.