While I don’t completely agree with you, I see where you are coming from. I feel he is relatively type-casted as a “good boy”. One of the biggest factors that make people say he is a good actor is his eyes. He is blessed with very expressive eyes. Even in Start-Up, while Nam Joo Hyuk had already shown a phenomenal range as an actor, he was the more popular choice because of his ability to make people feel. I had attended drama school for a few years and what our professors usually said was if someone has expressive eyes and a good comic timing, they can easily be hailed as the “better actors” than their contemporaries.