As some others have stated, I was a huge fan of the .Hack//sign series. When I saw roots, I was very excited to see the next generation of characters. However, I quickly got over that excitement.
As others have said, the pacing is off. Nothing much seems to go on for large chunks of time. On top of that, one of the things that really turned me off were the characters in general. It's like every griefer from every MMO you've ever played all banded together in one place. I can't stand those people in my games, and they're not any more entertaining when I watch them animated on my television. The heroes aren't really much better, and it's hard for me to get on their side, or become emotionally invested in their quest.
Whatever happened to wreck The World, it wrecked the francise too. This is for die hard fans only.