In my experience people generally do try to do good for other people if they can. If it doesn't cost too much time, money, or effort they will. I think most "bad" is something that comes out of self interest (not that it is a bad thing) blinding people to the effects they have on others around them. People want or need something and they learn to ignore others around them to get what they want. Few people manage to build awareness of this process as thy go about their lives. Most people actively try to increase their ability to ignore this. So in short, people aren't necessarily bad, they will just only try so hard to be good.