A major part of the problem, I think - is because the developer decided to try something new with distributing the client to customers on Steam. They decided to go with a small 3GB pre-load and then have the game download the rest of it as you boot the client up. This approach, I found to be immensely retarded and pointless. Instead of forcing everyone to use this new streaming approach, the developers should have given people the choice to play the game once 3GB of the client was downloaded, but also allowed people to continue downloading the full 30GB client - like the Battle.Net 2.0 launcher does. It's not very difficult to see why so many people are up in arms over fixing a system that has worked perfectly fine in the past (pre-loading the entire game before release). It's been a few hours of outrage from the community now, and there is zero communication from the developer.
It never fails to surprise me that prior to the game's launching, the developer(s) of various AAA titles can't wait to hype their game up with constant twitter messages, facebook updates and other media appearances. You couldn't get them to shut up about their game being the next best thing since hot bacon. Except when you need them the most, like when their AAA titles break apart like frail paper constructs under the duress of launch conditions, then suddenly they're not so keen to be speaking as much anymore. Heads up to the devs - do the opposite of what you guys are currently doing. You already took our money, and so we'd like for you to tell us that you acknowledge that something went wrong (and that you are also massive tools, but that's optional).