I never found Nog all that interesting, or that developed. Take him out of the show and nothing would have been any different.
I loved Nog but yes, I still agree.
If he was developed or not, his role didn't effect the show in anyway that would have made a difference.
Morn got a story simply because they had to create stories to stretch the season out.
While the writers were spending time developing the secondary cast, they completely and admittedly dropped the ball on developing a main cast member- Jake.