That hero is so naïve it hurts. He seems to have some fairy tail view of how fighting and warfare work, that if it's not honorable, elegant and chivalric than it's bad and wrong. That's not how reality works, the enemy wont face you 1v1 or face you only at daytime, the bandit they faced in ch1 who ran away wasn't just going to turn a new leaf and become a productive member of society if he got away, if they caught him he would constantly look for an opportunity to kill them.