You are of course correct, don't know why I was thinking that. They are crap then. My apologies Blasphemous, I was under the impression they also reduced damage. From a few years back, thought that that was what they actually were supposed to be. A trick item thus, the same as wand of ball lightning is a trick item, like many.
This makes me wonder whether the missile modifier wasn't actually meant to be a damage modifier? Mmm, now I'm really confused about the gauntlets of eternal peace, why the heck is it a crowning gift.