This, to be quite honest. That some of the documents show larger-than-reported civilian casualties is sprinkles on the cupcake. When Wikileaks received this cache of classified documents, they honestly didn't care what was in them; by Assange's own admission, they hadn't even looked at more than five percent of them by the time they were released. They posted the whole kit-and-kaboodle online for download in the hopes that the public would do the footwork for them and find something juicy - blatant abuse, perhaps something along the lines of My Lai - which Wikileaks would of course get heroic credit for "exposing". They assumed said juiciness exists somewhere in the 90 thousand documents because 1) they're classified and 2) it's the US military, who are evil.
The problem is, nobody is finding anything really all that smoking-gun in the documents. There's no "there" there.
Well, scratch that - there is somebody who's finding something in them: the Taliban, finding the names of its next victims.