That's true if the player are there solely to disobey the rules and be an asshole, but there's a lot of people that just doesn't understand/know the rules in the first place and a simple warning by just a user is in a lot of cases enough to make them stop doing it.
But even if you don't see yourself making a change by telling them to stop, it will still show your dedication for the server and its community because you are actively trying to create a fun environment for the rest of the players to be in. That's a huge positive reason to make you an admin; because you care.
But I have to ask, now when you want to become an admin to prevent these situations.
Why haven't you written reports/talked with admins so they could fix it when you saw yourself not able to do enough?