As stated in the example nodes:
Apathy is not the opposite of love
The Opposite of light

Just because we can prove that a space is "not" filled with a thing. We cannot assume that it's opposite is present. It's is a common societal symptom to do this, at least in thought, we assume that the absence of truth means that lies are rampant, when truly there are two options. It could be that there are lies, or there could merely be silence (ok maybe that's a bad example, check the nodes listed above for better ones). When a node is not voted up, do we then jump to the conclusion that it has been voted down, I don't think so. We see the possibility that it could be hanging in that 0-reputation limbo. This trend is commonly found in people who see the world in a black and white context. I pity them.