Do you mean your question seriously? There is one minor thing stopping me from completing the Dark Reach Citadel: it cannot be done solo. There are two minor things stopping me from completing the Sky Cruiser HM: it cannot be done solo and it is too high for me, I cannot do that even with a group. Why is it HM and not NM?
Groups would go for the instances which make sense for them, where they can get items needed for their progress. The Dark Reach Citadel is not one of them.
I hope for more luck in the next event.