I'd disagree. If you copy the playlist, then you've got a link to the playlist, so that if that playlist changes, it changes everywhere it's referenced. If you want to make a duplicate of the playlist that's separate, you need to create a new playlist that contains the same songs.

Now, it's possible that there's a problem in that there's not an easy way to do that in emplode, especially with nested playlists, but, IIRC, jEmplode has a feature to do exactly that.