I like how Kim's patience and faith are both his biggest strength and his biggest weakness as a character. He's an exceptionally loyal person who's able to handle a thoroughly broken individual with just the right touch...And also a person who, through his true believer tendencies, is still able to overlook genuinely despicable behavior on The Detective's part because he feels a bad cop is still better than no cop. It's possible to play the game in such a way that Harry is a gigantic fascist piece of shit, yet Kim still vouches for him in the ending as much as he would if Harrier were a total saint.
Reflects the fundamental complexities of interpersonal relationships. A person's strongest talent can also be their single biggest flaw; This also interacts nicely on a thematic level with the way the game penalizes stat dumping.