It would be lovely if that is the case, but for some, they use hatred and anger as their fuel. They hate indiscriminately. But that's what makes them so useful.
Hatred and anger are very inefficient fuels, you can always strive for better. If hate is what makes one useful, imagine what they could do with the good of their heart. Hate *can* be overcome, no one ever said it was easy, but it can be done.