I think that everyone is a good person, even if it is really really deep down. We all are just trying our best to cope with the horror that is life, and oftentimes we can’t. Some of us will talk it out, others will take it out. Of those who take it out go one of two paths: self harm and bullying/persecution of others. Talking is definitely the better option, but requires trust and that is something that most of us tend to be frightened of giving. The men Atticus described as having “blind spots” are people whose emotions have been pent up for so long that they are being released in the one way they know how: anger. This aggression causes them to want to hurt whatever is causing them stress and anything that they dislike as well, and if anything gets in the way then they are just fine with taking them down too.
Personally I avoid anger like the plague, because if you take it out on others all you do is create more monsters in the world; and the world really doesn’t need any more of those.