I digress. Here I intend to address the 'new' breed of metamods. They have a stated predisposition against negative mods (here, for example) but are willing to consider the content of a post. Looking at the negative mods:
Troll and Flamebait. Both of these mods suggest that the moderator knows the intent of the poster. Although it may seem apparent, the individual could be misguided, stupid, or (gasp!) even correct. Regardless, since we cannot glean intent (with certainty) from the post, these mods are always Unfair.
Offtopic. Unless a post is way out in left field, there really isn't a need to use this mod. It may be a crutch for a moderator who doesn't want to sound 'mean'...or a blind for a moderator who just doesn't 'get it' and wants to hide a post that is over his head.
Redundant. One man's redundant is another man's detailed shade of meaning. Again, tough to apply, except to the karma whores who have posted the full content of a linked article...for the third time.
Overrated. The chink in the armour. This moderation is not subject to metamoderation. It can therefore be abused, and should probably be eliminated. To quote (approximately) a fellow Slashdotter--unfortunately, one whose name I do not know--"the Offtopic mod is like saying, 'it sucks, because.'" It just doesn't seem to be a good reason. It fails to explain the reason for the moderation to anybody--poster, other moderators, metamoderators.
So what's the missing mod? I've just finished saying we can dispense with one moderation already--why replace it? The new mod that I propose is -1, Factually Inaccurate. Sad as it is, there is currently no moderation appropriate for a clear, polite, reasoned post based on objectively incorrect information. These posts may be flagged as Trolls or Flamebait because moderators don't know what to do with them. Moderators may throw up their hands and just mod up correct replies. They may use the flawed Overrated mod.
None of these techniques exposes the moderators thinking to the poster, and moderation leaves them open to vindictive (or 'corrective') metamoderation. By introducing a -1, Factually Inaccurate mod, metamoderators will be encouraged to check facts for themselves--read more of the thread, and so forth. The reason for the moderation will be crystal clear. Finally, the moderator will be encouraged to know his stuff before he goes out on a limb and claims a poster is wrong.