The reason was surrounded around the news of Google's Singhal around the swiss army knife analogy and if that is Google's true intent. Go read up about that if you do not know what I am talking about.In short, the SEO space is kind of mixed on their feelings of fearing or being scared of Google's end goal with the Knowledge Graph.
Most said, 45%, that they do not fear Google's Knowledge graph but 17% said they sometimes do and 37% said they do fear it. So 55% do fear the knowledge graph on some level and 45% said they do not.
Forum discussion continued at WebmasterWorld.