Hi,
I completely agree with you but at times a few of my clients request sales order so that they can make remittance on basis of this document.
When above is the case, I have to close a sales order and then cannot edit it as that is exactly how my delivery note and sales invoice would look like, which goes with the export documentation for customs purpose.
When above happens, I am not able to use sales order to add more items, and bunch them for delivery.
I agree, it might not be as useful to everyone, but if at all it is a easy fix, considering there are no implications to GL entries, it would be a good option.