Wow, it's almost as if the game being made by Americans accidentally highlighted the imperialist and oppressive elements of samurai culture without a complete lack of criticism towards it. Even Kurosawa would be disappointed (typically featured the peasants and poor samurai as the primary heroes/survivors in his jidaigeki), Kobayashi is just laughing from the grave)
Really though, I guess we haven't learned from Spec Ops: The Line
probably the best in-universe explanation is just that he's the son of a lord and thus everyone want to lick his samurai zori