Sweet cabernet sauvignon? Give it 90 points!
Well, sometimes. Like any public information available today you have to consider the source. Just because a story is distorted by Fox News or CNN doesn't mean all news sources are useless. I suggest the same is true for scores. If you are familiar with a particular reviewer and understand what his or her scores represent, they can be very useful. But you must consider the source when considering a score.
The bigger problem is that scores don't tell the average consumer what they need to know. A score doesn't describe a style and most people want to buy the style of wine they like. If a label or review identified relative levels of sweetness, acid, tannin, body, bitterness and alcohol it would be a simple matter of finding wines to fit your style preference. There was a system developed in Australia to provide this exact information in a simple graph, which could be on every back label. It's a crying shame it never caught on.