There was a flurry of conversation here some months ago when someone who left the plastic on her bags found that it did, indeed, damage the hardware over time. I understand not wanting to scratch the hardware, but the plastic is truly not meant to stay on the bag. Reminds me a little of keeping all one's furniture in plastic slipcovers forever to avoid damage to the upholstery. Yes, it makes the furniture nasty to sit on, but one knows it's clean! Anyhow, clearly there are some strong feelings about this, so hopefully if a client speaks up and says "please don't" most boutiques will oblige. For me, treating any consumer product as a ceremonial object is one step on a slippery slope toward the sort of relationship to material goods that I don't want to have, but that's me. . . and I think there are cultural forces at work here, too, as our French contributor suggested.
This would be an interesting subject of study: to some, a well-used bag suggests a desirable level of wealth and ease ("Oh, this old thing?"); to others, the more pristine the item, the better. A lot of this is about something called "signalling" theory (in evolutionary psychology, economics, and other disciplines). Fascinating!
Sorry, pretty off-topic there. Never mind.