Just a thought:
Maybe the OP knows what is SOP or NNOP or what have you. However, maybe he wants to know theoretically if this makes sense or why Boeing doesn't consider this, etc.
To say "because the book says so" isn't really much of an answer.
Maybe not all runways require us to go to Flaps 0.
What if we could fly? If God wanted us to fly, we'd have wings.