The ability isn't intended to alter someone's alignment, just aid in making them see things your way. It's opinion based, not alignment based. When I said "neutral" earlier, I meant the hostile or disagreeable feelings someone may have had towards you lessen to a degree. Each time you would "turn" someone, it would lessen the hostility more or make your arguments more convincing, eventually leading to a full-on change of temperament during that encounter assuming the turn attempts succeed. Eventually the effects would wear off. Plus, this adheres to the DM's wishes of having an ability that focuses on the cleric and not the group.