I may be somewhat biased since I both judge wine competitions and run a few of them myself, but I find that despite the criticism they often get wine competitions can be very helpful for the consumer. They offer a way to weed through the tons of wines that are out on the market and provide a service that is unique.
Critics of competitions will say that they are useless and that scores given to the wines entered do not matter, but I would have to disagree. Most competitions are careful to choose expert judges, and each has different criteria. Some do not allow winemakers while others prefer to have a technical palate on each panel. Each panel tastes through a series of wines "blind", i.e. knowing only the basics, sometimes just grape variety, sometimes vintage and price.