I didn't see the earlier thread, but perhaps the difference is in how things were worded? I quite often see pairs of comments posted at the same time and making exactly the same points, yet where one post gets voted up and the other doesn't, simply because one comment is better written than the other.

I imagine that this is even more important than usual in this case, since when the message is "please be good" there's really nothing except how well the message is worded.