Since people like to use that bullshit "it's meta!" excuse for MGSV's shitty plot threads, allow me to suggest that Miller is the one who represents the player, not Venom. Stuck in an empty world with the facade of openness surrounded by emotionless cut-outs with awful or no dialogue. He's portrayed as the one making psychopathic decisions but he's the only reasonable person in the entire game. Everyone else is batshit and totally nonchalant about it, including and especially Venom. Huey is also grossly mishandled to show the "other side" of this. It's terrible writing and fails to advance the characters in any way, they all regress except for Miller. Huey is just comical madness that comes completely out of nowhere for no reason other than to justify Strangelove's death, which is yet another justification of that stupid child genius plot point in MGS4.
MGSV is all about attempting to justify previous nonsense writing. Not explain them. Justify them. Each justification only muddles the plot further and makes it even more inconsistent. At some point Kojima lost the ability to write a compelling story and focused on the worst aspects of his previous ones. Venom is nothing but a dead leaf in the wind and none of the game's emotional scenes, save Shining Lights, does anything to give him personality as "Big Boss." The Paz ending only accentuates his original personality, and there is absolutely zero payoff when Venom learns the truth. Most scenes in the game are a waste of time or absolutely poorly placed, such as the Low Morale scene being restricted to the player not knowing how numbers work instead of being part of growing and advancing the narrative.
