All you end up are the trolls who do their best to toe the line while provoking other people to step over it, and the sort of people who think a conversation where everybody follows the rules yet no-one says anything of substance is preferable to a lively discussion. You end up driving away the people who just want to talk about things they enjoy or are interested in, and don't particularly care about adhering to your rigid social system.
People are people, not automatons, and the system of curating discussions should reflect that. If someone is acting in bad faith, waiting for them to violate the letter of a rule that's been written down before you do anything about it just allows that person to drive away more of your actual desired userbase.