Reverse Alchemy
Despite the ex cathedera tone of someone looking down from the heights of literature on the swampy plain of 'commercial fiction', Philip Reeve's diatribe against steampunk nails the abiding sin of all genres - too often the golden coin of originality is turned into a ton of commercial tin.
EDIT: Diatribe deleted on Reeve's site but still available here.
EDIT: Diatribe deleted on Reeve's site but still available here.