There’s been a lot of debate on this over the years, but overall my experience is that ninja looting is good for the player economy. It supports independent merchants and merchant related factions much better than trying ‘dungeon’ to obtain inventory. When you ninja loot, the finds typically go to one person or organization. Monster spawns aren’t lowered and more items are available for another player within 15 minutes. There’s also a good deal of risk involved here, especially in higher level areas - so as noted above, it’s a pretty unique experience to navigate. Dungeoning usually results in the finds being split across a party, making it difficult for one party member to obtain much for a shop unless all of the other members work for them or are in agreement to receive a cut later (that typically doesn’t go over well in my experience). Enemy spawns are dropped to 0 and the area isn’t really viable for a ninja looter or dungeoning party for 6ish - 24ish hours, depending on the growth rate of the area and what kind of spawn the player(s) are looking for.
I’ve been playing here 5+ years and can count on one hand the number of times I’ve entered a dungeon that has been looted so recently by another character that no loot is spawned for the dungeoning party, so overall I can’t say that has really been an issue for me or the people I’ve played with. There’s only been 1 time I had someone sneak past a group I was dungeoning with to loot out from under us. They made themselves known at the very end and it was actually a really cool RP encounter. I would agree - this would be pretty inconsiderate to do, especially on any kind of frequent basis - but my experience has been that it is extremely uncommon. I would agree with the sentiment that someone solo’ing an area (often inappropriately low for their level) is substantially more common.
To comment on the ‘loot monsters’ mentioned above, there are actually a good number of them on the server. While they aren’t in every location, a few of them are below:
Supreme Witches/Warlocks
Hags
Vampire Wizardess/Sorceress/Matriarch
Alhoon
Lich
Harvest Temple - Boss
Disciples of Hotep
High Priestess Hotep
Hazlan - Efreeti
Bebilith
Fiendish Fanatics
Demonologists
Prisoner Slayer
Malthor
Overall, I think what is in place on the server works well to accommodate a number of different play styles.