The problem in summarizing news manually is that it takes too much effort for a human to do it. The efficiency may be good, but as many news pass by, his efficiency will go down. (assuming that he's only the one summarizing)
Where this doesn't apply, and where I do think you're completely right is non-news articles: think blogs, tweets (although there's not much to summarize in 140chars), product descriptions, scientific articles, etc. These things are produced in much more volume and much less workflow around them.