Yes, I'm an idiot
... I've forgotten that we can't have it possible that someone ignore an admin or gmod, as they might miss something important (even including announcements). The change has to be reverted.
Again, I'm sorry... If this diary moderator (or any moderator) is giving you trouble, please report them to either a gmod or an admin so that something can be done. Otherwise, you can always ignore them with your mind (by just not reading anything they post/message).