When you give someone a present, it is nice to give it to them in a wrapping. You don't just hand someone a "toaster" - you put it in pretty wrapping so they have fun opening it up. The same is true for wine bottles! You don't want to just hand someone a wine bottle, or worse yet, give it to them in a brown paper bag as if they were a wino. Many world traditions emphasize the decorative wrapping of a present, to give the recipient a sense of excitement as they unwrap it. The same holds true with wine!