You as well put up quotes that do not have context.
Below is a quote in Prince of Crows. I did not create this thread to argue about what this came to though it came to this and I just went with it. ADB wrote Betrayer and Prince of Crows.
Night Haunter: "There was no other way."
Sev: "No? What other ways did you try?"
Night Haunter: "Sevatar…"
Sev: "Answer me, father. What politics of peace did you teach? What scientific and social illumination did you bring to this society? In your quest for a human utopia, what other ways did you try beyond eating the flesh of stray dogs and skinning people alive?"
Night Haunter: "It. Was. The. Only. Way."
Sev: "The only way to do what? The only way to bring a population to heel? How then did the other primarchs manage it? How has world upon world managed it, without resorting to butchering children and broadcasting their screams across the planetary vox-net?"
Night Haunter: "Their world were never as… as serene as mine was."
Sev: "And the serenity of yours died the second your back was turned. So tell me again how you succeeded. Tell me again how this all worked perfectly."
Night Haunter: "You overstep your bounds, First Captain."
Sev: "How can you lie to me like this? How can you lie to yourself? I stand here, inside your mind, witnessing a theatre of your own memories. Your way is the Eighth Legion way, now. But it has never been the only way. Just the easiest way."