Benjamin's proposition that the authority of art is lost seems true. It resonates with me personally as well. I know I would rather see something that people are crazy about than hear them describe it to me with words or letters. And now that images of everything are available it seems like everything is over saturated. Personally, because art is so available I know that I don't tend to be excited when I'm in its presence. It's like living in a city your whole life versus visiting a city for the very first time after living on a farm your entire life. Reproduction does seem to be a good thing for the means of exposure, but it does seem to make people less inclined to appreciate art. I think it takes away a huge part of the experience or rarity of art pieces.
On the link above there are pictures of Stonehenge and then later photos have people next to them. Just as an example it shows how large they actually are, and even seeing these pictures you can't quite appreciate the megalith.