The game hasn't even been out 1 day, you cannot review a game you have not fully played.
People are also incredibly whiny because of login bugs etc which while are a problem do not in any way tell you how good the actual game is, every game is buggy in launch that's how it's always been, be thankful that Blizzard are one of those companies that actively fix these kind of issues and have an amazing customer support.
People like to badly review games because of factors that truth be told aren't actually part of the game itself. The amount of times I've seen games get negatively reviewed by idiots because they are on steam for example is absurd.
I've thoroughly enjoyed what I've played so far.