Unfriendly/ rude moderation is what happens when the tools in place to try to keep the site’s content in alignment with the person’s vision fail.
Not enough votes. Not enough time. Poor filters. Too low a barrier to post a new question.
People then turn to social tools. Rudeness ensues.
An open question is what is the vision of the site... and there are probably many of them.
Most of the community seems to be aware of the issue when prompted, but most times when I see moderation happening, it's not as friendly as one might hope... I always try to provide helpful pointers and comments for the author, if I happen to notice it in time.