The main problem I had with D3 was how utterly mindboggingly BORING the loot it. "Oh look, attack, health and defence".
In diablo 2, you had stats you had to balance to equip gear, you had uniques that actually did matter, and if you wanted an item, YOU HAD TO TRADE IN PERSON!
This was actually one of the things that made D2 so fun, to trade yourself from a mid tier unique, to a high tier if you knew which items were class-crucial on the way up.
And, you had incentive to play with randoms, at least until pick-up hacks and botting became standard and killed the game (and really, what the fuck happened there blizz? The bots have been using the same fu**ing backdoor to spam games for the last 6-7 years...) Doing an 8 man act 1-5 game was brilliant, lots of fun in the chat, challenging teamplay, while diablo 3 punishes cooperation, and makes every gamer into a social recluse.