Keep the best stuff in a dungeon in a plot locked chest. Have the key on the boss critter. Want to get the best stuff in the dungeon without fighting the boss? Hope you can pick pockets!
Just an idea.
This idea just makes the ninja looter kill the boss, which I presume you feel they avoid doing now because its not dooable or too dangerous?
So not only would they be looting the dungeon, but getting the highest XP kill as well. This lowers the spawn level.
Somehow this is a preferable alternative? I do agree with some of the nicest loot actually being on the person of the boss. Its that way with the Alhoon, the 4 Hags and the Lich. And I have noticed high spawns without the loot and the final boss before, because someone killed them and them only. The loot on their person is the only reason the spawn was tampered, so its tit for tat.
There is not any perfect answer, because there is no way to please anyone that perceives taking items through subtlefuge rather than brute genocide. The truth is, either way, you earn the goods. Anytime a place is too easily done, there are changes made to make the task much harder. There honestly not any place on PotM that does not pose a serious risk to a would-be stealth gatherer.
I do know one thing though, the original poster very well could have started over frustration from something that was not even ninja looted. Not everytime a place is void of loot is because of a ninja looter and nor is the practice widespread or even common on potm as its perceived by some of you.