I meant to write something about this for some time now. There should be a lot of other topics on this but I could not find them because of all the bot-complaints (on which I totally agree too).
But this is about the closed dungeons and 4-ppl-groups, about trolling, loot and how those dungeons reward people who greed/grief and ruin everyone else's fun.
I wanted to write about that at length but then a buddy showed me the youtube-vid where someone else explains it all. So..
https://www.youtube.com/watch?v=KLBHjwCw088
I really hope for something like a lootroll (against chest-running greed) and some better and more group-friendly bosslootdistribution.