Normally I'd be far more annoyed by an MC who refuses to kill bandits who are clearly out for blood themselves, but this case is a bit different because the MC is, at the end and very openly, a cheater. He hasn't been, even once, in real danger so far. He could have escaped the dungeon bosses as well with perfect certainty, so I don't count those encounters that dangerous. He also hasn't needed to protect anyone, so that a failure wouldn't be an option. His way of safely sneak attacking all the time doesn't build his character. He's still 90% the peaceful Japanese dude, despite everything he has done. He's not committed to anything, either, and far from being mentally prepared for any conflicts with other humans. Yet he's trying to prevent both a civil war and a whole war of invasion. You can tell he hasn't thought things through.