I don't get the obsession to keep the game exactly the same, the original is still there right?

I think you are making a false dichotomy. If they replace FFA loot with personal loot, then one can claim that they changed the loot system. If they keep FFA only loot and introduce an option for personal loot, the game is both preserved with FFA-only and has a selectable option for non-FFA that can be segregated at game or character creation.

This does not risk people thinking logically that D2R is repeating the mistakes of W3R.