They don't really leave it out of the equation, though they don't explicitly state how it factors in. The issue is that a high profile case that people want to be prosecuted to the fullest extent is being used as a wedge to force a large undertaking (producing the unsecure firmware) to be made. Future requests from law enforcement on much smaller cases would then only require the smaller undertaking (signing the existing firmware), and resisting that court order would be significantly more difficult.