I agree that discussing forum etiquette is useful.. especially when discussed among forum participants (as opposed to enforcement from moderators.) In most cases like this, both parties are good people, and neither intended to offend the other.

There are many reasons why forum communication can go wrong, and most of them are easily avoidable. Discussions like this create new awareness in the whole group of how to avoid throwing gasoline on a very small fire.

Before the thread, there were bad feelings... now there are none. IMO, that justifies the existence of the thread.