Basically this: how I think and believe humans should behave is not the way they actually behave. Many are hypocrites, saying one thing and doing another. They can be cruel and selfish, from simple malice all the way to repeating history through wars and killing. You never really learn the lessons given through life, and the worst part is that you teach your children to do the same thing. The thoughtless herd mentality, following trends and propaganda like it came from the sermon on the mount. The utter disregard for life and the planet, trashing the environment, and especially the abuse of other "lower" species. You're the only creature that goes directly against the flow of nature and it's killing the planet and everything on it. Even Gaia is trying to scratch you off her back.

It's not that I have hate in my heart, quite the opposite in fact. It's just hard to love a sentient species that acts like a virus or cancer.