Andre Engels, your position is: changes to interface should get consensus before. So, when a new extension is added, or changed, and there're several new (renamed) messages, should i kindly ask permission for translating it from english? Don't be ridiculous! I translate them, and if i make mistakes or something is wrong, another one will change it. It's a wiki, do you remember? Changing outdated messages is fine to me. And if the other version is equivalent, there's no 'large change'.
The action itself was hostile. On Wikipedia we work with consensus, not one person doing something and the rest being given a fait accompli.
We also [[Wikipedia:Assume good faith|]]. Asking a poll on every change would [[Wikipedia:Don't disrupt Wikipedia to illustrate a point|disrupt Wikipedia]]
It has been argued that others want to be part of the decision of what are project specific messages. It has been argued that others want to know what is going to happen. It has been argued that others want to be part of the decision on which message of two similar ones is the better one.
*Then*, it should be argued, but only after it was asked.
That's your opinion. Mine is that there was. It would have been better to discuss this in advance.
And teh sysop's opinion that it wasn't :D
Someone who does that and afterward does not realize that it's a bad idea, breaks it.
He doesn't need to realize that "it is a bad idea". There isn't even consensus about if it was a good idea or not! You can simply make policy saying: "Noone can change more than 5 mediawiki messages in a month without having asked the community". Then you can claim bad faith (or ignorance...). Anyway, i'm sure this user wil think twice and five times before changing a MediaWiki messsage.