Here's a theory. PSA are definitely trying to control pop reports but perhaps they are also trying to stop the practice of people re-subbing a PSA9 that looks more like a PSA10. The way to do that is to intentionally damage the card so that it will not be cracked and resubmitted. It's very easy to do and there's no comeback. A quick scratch or bang on the corner....Same. Got one returned an 8 from PSA with a bent corner.
I 100% never send those with dings, unless I really know about it.