The mystery revealed:
"When an editor's lucky, the piece comes in chiseled in immortal Carrara marble, every semicolon in place, ready to be wheeled into the Uffizi Gallery -- that is, straight to publication. (A very rare event.) A good editor knows when to leave a piece alone. Practically every writer has had the unfortunate experience of crossing paths with editors -- often inexperienced ones -- who feel the need to do something, just to show they're doing their job. This is almost as frustrating as the too-many-editors problem, in which a piece bounces from a senior editor to the managing editor to the executive editor, each of whom gives contradictory instructions, and finally ends up in the hands of the editor in chief, who after Olympian reflection pronounces that it was better the way it was when it started. It is experiences like these that lead writers to engage in one of their favorite pastimes: bitching and moaning about the lameness of editors.
Good editors work with and not against a writer. They calibrate how aggressively they edit according to how good the writer is, how good the piece is, the type of piece it is, the kind of relationship they have with the writer, how tight the deadline is, and what mood they're in. But an editor's primary responsibility is not to the writer but to the reader. He or she must be ruthlessly dedicated to making the piece stronger."