In Haejoon's case we find out that the ghosts were real, but he still had to deal with society treating them both like pariahs. He also convinced himself that his mother was sick and became afraid that he was mentally ill as well. It's a very tragic story. I also think that his mother could have done more to be understanding towards her son. It was pretty obvious that he was terrified. What's even more frustrating is that in the first chapter Haejoon says that his mother was afraid of the things she saw at first, but eventually got used to it. So she knew how terrifying ghosts could be and she couldn't have been gentler with her own son? Her behavior also came off as bizarre to the neighborhood and made Haejoon a social outcast.
To be honest, I dislike Haejoon's mother more than Juwan's. She should have stopped when it became obvious that Haejoon was feeling more than discomfort and was actually scared. But she kept pushing and just laughed it off when he cried. I wonder what Eunyung's family is like. It kind of seems like a trend so far that everyone has a difficult relationship with their mother.