Because if something is amiss, my staff need to go into the warehouse with the packcing slip and check the discrepency. Also, , our pull and ship process is two part. My pulling staff need to be able to take the packing slip into the warehouse, and scan it, to make sure they ar epulling the right item. The shipping staff would then do the verification process when packing. The data is there, we need to be able to define how we use it.
Also, using the SKU as the barcode is not reality. SKU and UPC are COMPETELY different things in the real retail world. This needs to get fixed, and you need to imporet UPC data from shopify separately - that is WHY they have different fields.