since unregistered users can't change their language, how would you propose they set it back to english if it is set to something they don't at all understand? if i go to greece and get some sort of greek gibberish from services, for example telling me to change nick or be killed, how will I know..?
And personally, i hate auto language.. it never gets it right.. i live in a country with just 3 language, nvm countries like india with 100s, and more often then not, it gets it wrong..