Please clarify why Diadem is or is not an exploratory area, with suggestion

[LunnaRavenheart]

My expectation was there will be objectives based on difficulty you entered and after you complete them you will be rewarded by some reward/loot/mats.
Like there will be no usefull mats or drops inside diadem but you have to work together eg nodes are guarded and you need to like kill 30mobs, gather 200 nodes, collect 200 fishes. All just quest items inside. But after you complete all objectives, reward / chest will appear for group based on level of completition (maybe on time?).

So you have work as team on all objectives to get some reward. I think that it will work better than current state of Diadem.

And also they should randomly generate that islands every run, so you always have blank map and things to discover because like you said they are Exploratory missions but after 1 run, there is nothing to explore.