People seem to believe that the Diablo 2 stat point allocation has been lost. Not true, the stat point allocation system has been migrated onto items. You still choose what stats you want to 'level' through choosing items with that stat. Itemisation in Diablo 3 is what stat allocation was in Diablo 2. The itemisation system of Diablo 2, allowing you to perfect your build through skill bonuses/massive damage bonuses tailored to your build, was effective in hiding the fact that the game was based on a RNG.
Diablo 3 makes no such attempt to hide this fact, it is quite happy to have its players simply chase numbers. RNG = 1980s game design and while Diablo 2 shone it up effectively by giving people something solid to aim for in unique/set items that were tailor made for each build, Diablo 3 has gone down the tried and tested 'Let's throw some pretty graphics at them' route. The result is a repetitive game of number crunching and smashing barrels.
The unique items in Diablo 3 are completely pointless. Apart from their scarcity, the fact that you have to level your gear constantly as you play detracts from the game completely. When finding the relevant upgrades consists of nothing more that browsing YET MORE numbers and choosing what you feel you need as opposed to playing or interacting with other players in game it feels yet more like a spreadsheet than a game.
I can understand why a lot of people like this game, there is a lot to like about it. However, I can understand why people are upset and disappointed also as detailed above. I'm really looking forward to the expansion to this game as Blizzard will have to pull out something really magical, or even rare, to get the sales figures up.