Why do items 'Delivered Late' automatically trigger a demerit?

[gurlcat]

Can anyone explain why the 'Late' report has a header saying Items That Weren't Shipped On Time but then in the list of items below, they are classified as 'Indicates Delivered Late' and they count as not shipped on time, even if tracking shows you clearly DID ship on time according to your handling time?  Thus far I have been able to get CSR's to change these to non-calculated in my scores, but why should one have to go through the trouble?  Why can't it just be programmed to recognize that the seller did exactly what they were supposed to, and that any lateness of delivery was the carrier's doing?  
I already reach out to any buyer whose package appears 'stuck' before they get worried or annoyed enough to contact me, and start a missing package case if it remains stuck, and this is why I have never had to issue any INR refunds or get any negative feedback for late deliveries.  So it's pretty irksome that I have to remember to monitor my report and beg ebay to "forgive" something I didn't do wrong in the first place, a month after keeping those buyers personally assured until they receive their items.   

[pjcdn2005]

As long as you have an 'accepted' scan from the carrier within your handling time you are not supposed to get a late shipment ding. It's odd that you are.

[evry1nositswindy]

I have had several shipments that I shipped on time, but they arrived late.  I still show 100% tracking.   Did you ship with tracking?