The item drop rate in Diablo 2 wasn't wonderful either in terms of finding useful things consistently. The game had a shitload of dupes and stuff bloating everything up, tons of MP games were just dudes dropping duped items everywhere on the ground.
Where Diablo 2 differed was that you at least got a large variety of set, unique and rare drops that you could mix and match on different characters. Stuff that wasn't immediately useful could at least be saved for set completion and use on a different character. That is another problem with Diablo 3, there is no reason to roll other characters (one for each class mostly) due to both the skill system being so simplistic and respecs. Even with the respec tokens in Diablo 2 (patch 1.13) you still could build wildly different characters with attributes and make further use of different items.
Items in Diablo 2 lasted a lot longer too due to the way the items and the games skill system interacted. Diablo 3 is more like an MMO game where you replace things regularly which kind of blows. There is no way to advance your character without doing so due to the way they neutered the skill/attribute systems.