When I asked the dev about that, the dev told me that warlord does not mean you are evil; it just means you will take a more aggressive approach, becoming tougher. Peacemaker is not the main path, as it seems you think. It's more for people who do not want to kill that much, as some people may not like the "mass murdering" kind of thing.
I see the peacemaker as an early Rick Grimes path, where he did not "kill the living," versus the warlord path, a more Shane, Negan, or Governor path; even the latest season Rick fits there after he stopped obeying his rule of not killing the living.
I think you are just seeing the game as if the peacemaker were the right path, when the warlord, for me, seems to be. I don't see the game shaming you for killing manhunters. Actually the best scenes from the game come if you are warlord.
Were you the same guy who complained that MC should not feel guilt after his first kill? Every person who is not a psychopath should feel guilt after they kill someone for the first time, good or bad.
But from what I see, the main path seems to be warlord.