Even if a group of four people all want what's best for the group, they can still have very different opinions on who will best-use each item. As-is the fastest looter makes that decision, and other players don't easily get to view the spoils even.
And often who gets the loot won't make a big-enough difference to hamper the party's progress anyway, but getting to see and equip the latest items is a big part of the fun. The system as-is rewards the fastest looter every time. Players can be a little bit selfish, have more fun, and still progress through the game just fine.
And then there's the convenience of the UI asking each player if they need an item or if they're just going to sell it. With a roll system I don't have to attempt to describe the stats to everyone in my party and try to sort out all the people who want the upgrade if they can easily see the stats and hit a button for that decision themselves.
I'm just saying many groups could realize benefits from a system that allowed for automated-rolls, and it's the kind of feature that is easy for uninterested groups to disable.
