Gameplay Scenario - 4 players take WP to Cata lvl 2 to run Andy, Fan out looking for stairs, each players fights and slays mobs. Items that arent Personal Loot distributed to them are all left on the ground spread out through the floor. All the items, the monster killer doesnt want are left on the ground with no one else able to interact with them. No one is going to reasonable retrace through Cata lvl 2, seeing what items were dropped for Personal Loot for them from other peoples kills. So those items that could have been looted by the Killer of the mobs go to waste. That loses loot in the games economy. Items that Could have been looted go to waste.
Gameplay Scenario 2: Player joins cow game late, after other players have left. Enters portal. Nothing is there. All those items that have potential to be looted by the new player are invisible and are wasted potential loot. Because the players that can interact with them have left.
Thats how Personal Loot affects the game Economy.
Are there systems that could be added to mitigate these issues? yes, a whole host of other systems could be added to ensure, missed loot is less common, so Personal Loot would have a smaller negative impact on the games economy,
Clarifications, Below things arent “Bad”, they are just systems that would need to be added to the game while Personal Loot in “On” to diminish the negative effects that can accrue with Personal Loot.
radius of Personal Loot activation(no one around you, you get all loot, only people in radius get loot, so leecher in town gets none etc)
mini map markers showing were “Good” loot is like Diablo 3 that has dropped for the player, so players can locate items that personal loot distributed to them that they might be close enough to easily see.
And having a system that when players leave a game for longer then a duration, their personal loot is marked as free loot.
How many game systems need to be added and tweaked and adjusted to TRY and get Personal Loot to work well with minimal downsides?
If you want personal loot, play in a private lobby, then all the loot is personal to you. A lot less work then adding it a bunch of systems to try and remove the problems people would have with personal loot option in public games.