To start I am against personal loot in D2 for personal reasons, but I want to further explain why you shouldn’t really believe some of the myths a lot of the posters on here are feeding you regarding the topic. I get that Personal loot was implemented fine in other games. These opinions are why it would not work in D2 which already has an expected distribution of items and playstyles.
The most common personal loot I see pushed is this concept where loot is either instanced or dropped and only seen/picked up by one player. Whether instanced or only visible/picked up the total amount of loot drops would not change between shared loot and personal loot. With this theory many suggest players should be indifferent. The problem is, most likely scenario they won’t be.
Here’s the issue. Loot dropped in an 8 player game is less than 8x the loot dropped in a single player game. If there is a situation where a player is only limited to their personal drops in multiplayer they will get less total drops in multiplayer runs than they would if they just played by themselves. Although this penalty ALWAYS existed in this game you see more drops in a multiplayer game so you don’t “feel” this experience happening. Essentially an 8 player game in current Diablo is each player gives up ~24% of their drops to be able to steal the loot of 7 others with the sacrifice they can have their own stolen. Personal Loot would just have you take the 24% hit with the benefit of faster clears and more xp. This is why many experienced players will explain to you its not smart to MF in public games. When it comes to high valued items you are ALWAYS taking the base hit since everyone in game is looking to steal it. You are LITERALLY betting on your chance to steal it from someone else.
Once players “feel” that they are getting less drops, they will do what players do, complain. To say this system will work you have to trust that the playerbase won’t push for more drops. I don’t have that trust and I expect we would see calls to reduce the 24% hit under the banner of “encouraging multiplayer play”.
Here’s why that can’t happen. If you have a situation where a player can buy 8 individual games and run them in the same game and have a better result than running them in separate games you have an issue. You will get players who buy 8 games to increase their drop chances. Here is the further issue, you don’t even have to have Players 8 = 8x drops for this to happen. If you have any situation where the players individual MF is used to calculate their personal drops this will be encouraged. Players will create an account to clear and then 7 accounts head to toe in MF so these additional accounts have their rolls calculated on their own MF (players will leech themselves). I know this sounds ridiculous, but people did this in D3 already and would have 4 characters running the same game to increase drops.
The most likely scenario with personal loot is it either creates an even more negative multiplayer experience, or it inflates drops. I haven’t seen a convincing experience that fights that. Timed loot would work though since it protects high tier drops, but allows sharing of other items.
But that goes to the next point, personal loot also does not stop leeching or ninjaing, it Automates it. A player can only “steal” an item from you if he was near the kill and in position to steal. This would mean he would also be able to be assigned personal loot. Rather than him having to outclick you for it, assuming you did all the work, now all he must do is stand there and the game gives it to him. In the 12.5% chance the game assigned it to you he cannot take it, which I guess is a win. Seen another way now you would get 12.5% of any of the best drops you ever seen in an 8 player game, that’s all that personal loot ensures you.
Finally, the pretzel. Players say this can be optional, but this only works in a situation where loot drops are never increased. If loot drops are ever increased and it is not carried over to shared loot the “choice” is eliminated. If you carry it to shared loot, you will then have solo players now upset for the punishment they receive depending on the size of the buff. If you buff single player as well, you start the problem all over again(single player > multiplayer). All that in mind, any increase to drop rates in any scenario opens its own can of worms.
TLDR:
The most likely scenario with personal loot is it either creates an even more negative multiplayer experience, or it inflates drops with the exception of timed loot.
If you read all of this in aggregate you will see personal loot disincentivizes someone better geared than you to help you out. Even in a rush, one of the best protections of someone taking good drops was they were too low to effectively loot monsters while you kill things. Now they will just follow you around and safely pick up their share as you clear. D2 has many features to boot these players out of games, but no one uses them because these people have no impact on your game since they cant even loot the monsters without dying. A large playerbase and personal loot will cause level restrictions on most games. You have enough players who want to join your game to meet the XP requirement so a player who cant help clear content is useless.
There are some idealistically thoughts out there that this will encourage undergeared character players to band together and beat the game as it should be played. This is possible but I have my doubts. Most good players know how to beat the game on their own. The players who would need this the most are the ones least likely to be geared or understand how to play the game. I don’t feel like I would want to join a gaggle of them to help them out and take a 24% loot penalty to do so.