I can see why some people may rate it low (both the early chapters and the premise), but the series has a great feel to it. All of the characters have a decent story to them and don't detract from the plot. Unlike most series where they try to explain why a character will take an action before it happens or as it happens, This series tries to have the reason as a small flashback that enhances more than just one character in the story.
The series'cruel concepts and visuals are something that people will shy away from but also paint a pretty clear image of things that people don't want to admit happen in the world we live in. Fans of darker series like Berserk, Kyochuu Rettou, and Ubel Blatt would most likely find the series interesting.
Overall the series for me has come off very strong and I do recommend it.