Archer,
I know you are disappointed, but HR is there for the EK business, not to further your career. The HR function is to hire the best candidate available at the time. If they interview someone better qualified than those already in the hold pool, the new dude gets the job. Any research on EK would have told you that this company cares only about the dollar, employees matter little here.
If you gain more experience whilst in the hold pool, your chances of the job improve. Hence the reason I suggest you keep updating. EK is not the only airline to do this, I know people who missed out on jobs with BA and QF after being in hold files for long times, while others were offered jobs straight after the interview.
The hiring of 100ish DECs has made a huge difference (reduction) in the number of new hires (FO) required. I think they were surprised that so many would apply for the DEC job when 1st year Capt pay is being offered, as there are much better deals elsewhere.
Good luck to you mate,
The Don