The 8 inch rule is for the primary purpose of reducing the severity of an injury on a pedestrian. If the forks are only a few inches off of the ground and you hit a pedestrian with the fork blade. You are going to damage many small bones in the ankle and in the foot, if the blades are up 8 to 10 inches you are going to hit a more stable and simpler designed area (2 bones) in the shin or calf area. That is the primary purpose of that rule (sad that I know that huh?).