Actually Bill, some publishers do exactly what you describe above.
When my copy of HE IS LEGEND arrived from Gauntlet Press, it was damaged. I sent it back and it was replaced with a book that had the same #....so obviously Gauntlet had some blank copies available. Once all customers had received their orders, I have to assume that after a few weeks, Gauntlet "numbered" the blank copies with "PC" and either sold them, or distributed them to friends and family.
I don't get the disdain for PC copies either, but I too am guilty of the same behavior.