Slipknot chose this phrase because they see the human race as a disease that spreads rapidly causing bad things such as death,war and so on. They are sick of the human race. They are sick of greed.They want a change and this is one of the things they strive for. They don't just hate individuals, they just hate the whole system. "The more I see the more it makes me Sick", "I can't help it I was born into this evil and I'm sick of it." - Shawn. "Besides all of us just being a bunch of spores and living in our pathetic little ecosystems, I as a fellow human am just tired of watching the majority of humans make mistakes. I'm done with it, I've had it. We are what we are, we just waste and we ruin and we corrupt and we destroy. To me, that's just waste, that's shit. Fuck people.
When asked why "People=Shit" Crahan says "We are what we are, we just waste and we ruin and we corrupt, and we destroy," so People=Shit basically because we are our own worst enemy, we are going to be the end of the earth and no one seems to give a shit.
The message trying to get across is that of the human race is depleating itself of the simple pleasures in life and that everyone is now fake. Fake meaning people, society, everyone, is now pretending to be someone else. Not caring about others, and just themselves.
In this act, they are a disease put on earth and we must show them the reality of life. They kill themselves, and or others, because they do not know what is going on in the real world because they are so wrapped up in the world politics and media, they hide reality from people because it will scare them. People need to know. People are the #1 cause of destruction on this earth and this needs to change, but the sad fact is, we can't. That is what they are trying to get across. | 
