12 Ways Bethesda Should Have Made Fallout 4
8. Story (Part 1) - Why The Focus On Kellogg?
Why was so much time spent literally getting into the mind of Kellogg and understanding his motivations? I can't tell you, because it never matters in the long run. We find out the guy who took our son had a tough upbringing on the way to discovering where he's hiding out and... that's it.
Seriously, think about the structure of Fallout 4's narrative. You come out the vault, track down Kellogg, learn where your son is through memories, meet up with him and choose a faction. Fin. He makes up about a quarter of what you 'do' in the entire game.
Kellogg kills your partner, steals your kid and is then revealed to be this potentially sympathetic figure drawn into a life of crime because of how detached he was from society itself. Were we supposed to do something with this information? It doesn't change how your son relates to you, there's no Stockholm Syndrome-esque implication that all the time spent with Kellogg actually made the latter something of a father figure - nothing.
The most useful thing from Kellogg is his pistol, and although that could be a brilliant commentary on his arc as a character, I think that would be giving too much credit for what's actually here.