It appears that there is a precedent in this forum to allow almost all posts that outright say to people "your post is dumb and stupid". But people are defined here only by what they post. That's their identity here. So claiming that someone is stupid and what he wrote is stupid is little different.
The practice also violates Guidelines already in place that dictate proper contact, civilized discussion and plainly not trolling users of the forum.
I know that there is a precedent also followed by mods, but it might be best to leave it behind. Few people see a difference between the two.