Dungeon runs should always be need before greed (ie, if the tanking shield of uberness drops, first dibs should be the tank, end of story). But the sad fact of the matter is that you can't always trust people. There definitely needs to be a better system in place to deter ninja looting. Boss drops auto-dropping into people's inventory creates the temptation for greed.
In a perfect world, people will hand it over to the party member who deserves it. But in a multi-class game where everyone can conceivably level up every class/job and try to justify holding onto items with the excuse that, "Well, my so-and-so can use it", I can see the potential for ninja looting running rampant if a proper system isn't put in place early on.
