We're on the same page here
I know that if I were running a game store, I would shrink-wrap all copies but one as a preview/shelf copy.
I hate spending an insane amount of money on a book only to find a page or more torn, tweaked, smudged, etc.
I think it might have something to do with the volume of traffic that a gaming store sees. For a small ma-and-pa store, the volume is low enough that their product is not damaged/compromised by shopper traffic. However, in the large population centers, and few gaming stores, the volume of traffic is such that shelfware becomes an issue.