Wiki is like a game.
The important point is that playing makes only sense if you play to common rules. If someone violates the rules or starts lengthy discussions about the rules - this way disrupting the game -, he spoils the game.
Imagine some people playing street soccer. Now someone enters the game "may I join?" - "Yes, ok". After a few moves he starts a discussion about changing the rules. The normal reaction in real life will either be: "Yes, ok, why not." or "No, play to our rules or move out". In real life people accept such quick decisions as making sense. Wiki visitors often do not want to understand - for whatever reasons - that it is justified that the current players define the rules. And that it is more important to have fun playing than going into rule discussions.