He can't really blame anyone but himself. He had his chance. I get that he was probably overwhelmed and thought he wanted to be with that guy but he never sat down with himself to think about his feelings. So now he's full of regret...It's true, you don't know what you want until you actually lose it. If they got back together, it won't work anyways considering the way Taejoo acted when Yoon woke up + Yoon seeing another side of Taejoo that isn't appealing, Taejoo doesn't like Yoon's job, and Yoon's feelings have changed. It's too late. Yoon already moved on and his heart is already occupied with Kwon.
He can't really blame anyone but himself. He had his chance. I get that he was probably overwhelmed and thought he wanted to be with that guy but he never sat down with himself to think about his feelings. So now he's full of regret...It's true, you don't know what you want until you actually lose it. If they got back together, it won't work anyways considering the way Taejoo acted when Yoon woke up + Yoon seeing another side of Taejoo that isn't appealing, Taejoo doesn't like Yoon's job, and Yoon's feelings have changed. It's too late. Yoon already moved on and his heart is already occupied with Kwon.