I was browsing through the [Badges page](http://askubuntu.com/help/badges) when I came across this one under "Moderation Badges". 

>  "Disciplined" : Delete own post with score of 3 or higher

I do not understand the purpose of this badge. If a question or an answer has been upvoted at least 3 times, it mean to me that it has been useful post (and it will probably be useful in the future too).

What is the explanation and some example case of the purpose of this badge ?

Thanks in advance.