Yep this should be all.
In the development of Nehrim the mainquest was the focus of the team, in the last part of the development some problems arrived within the team (some wanted to release earlier - Lord Dagon managed to let everybody stay on board till half a year later, when the final release date was set).
Because of that the time for developing sidequests was quite short and they simply didn't have the chance to do more - on the other hand most dungeons have some sort of short story linked to them, about which you can read in letters and books you will find in said dungeons.
For Enderal they planned better and got much more sidequests (even though not as many as Skyrim) and none of them are simple fetchquests.