The point is that people have an inner life which isn't necessarily reflected in their actions. Someone might do "good" things all the time, but if you could read their thoughts and see their motivations, you might not necessarily consider them to be as good as they appear. Similarly, someone who's done a lot of bad things might not seem so bad if you knew their inner motivations. Actions only give you half the picture (if that).

You also seem to be making a terminological point about when it's ok to apply the term "good person" or "bad person", but that's a red herring. You can use those terms however you like, but it doesn't have anything to do with what I was saying.