preach
Literally nobody is saying it excuses his behaviour. Of course it doesn't. But it does help us understand why he acts the way he does. Sadly hurt people hurt people
True but it's not about people /saying/ they forgive him. It's acting like they forgive him, and they love him etc. Which is fine in context because it's a fictional story, but I believe stories like these are a good opportunity to form good habits and be more conscious. That's why I love reading them- there's a lot of valuable lessons to take away with you to the real world and real relationships.
Even if Seungho was abused as a child it doesn't excuse anything he did as an adult, that's not how this works. It's makes us understand him better and empathize, but it doesn't erase how cruel, abusive and manipulative he's been. He has a lot to make up for before we shower him in love lol.