Because it looks fancier and more expensive.
9 wine judges from France, Belgium and the U.S. tasted French against New Jersey wines. The French wines selected were from the same producers as in 1976 including names such as Chateau Mouton-Rothschild and Haut Brion, priced up to $650/bottle… Although, the winner in each category was a French wine (Clos de Mouches for the whites and Mouton-Rothschild for the reds) NJ wines are at eye level. Three of the top four whites were from New Jersey. The best NJ red was ranked place 3. An amazing result given that the prices for NJ average at only 5% of the top French wines.
A statistical evaluation of the tasting, conducted by Princeton Professor Richard Quandt, further shows that the rank order of the wines was mostly insignificant. That is, if the wine judges repeated the tasting, the results would most likely be different. From a statistically viewpoint, most wines were undistinguishable. Only the best white and the lowest ranked red were significantly different from the others wines.
See The New Yorker’s piece for all the details and make sure you decant your plonk and serve it in appropriate glasses. It makes much more of a difference to your guests’ perception of the wine than spending up on a fancy bottle!