Actually, I think the analogy is pretty good. Did you read Janis Ian's essay on the impact of Napster/Kazaa on her sales? See http://www.janisian.com/article-internet_debacle.html. Note also the experience of Baen Books, as described at http://www.baen.com/library. They don't have Robert Heinlein or Michael Crichton for free download, but they have a lot of people who are trying to make a name for themselves (and succeeding, with the help of free downloads to spread the word.)
And in fact O'Reilly has made quite a few books available for public download as a way of boosting their visibility. As noted in the article, we believe that the positive impact is greatest for little-known works. For works with high visibility, such as most O'Reilly books, there is a "progressive tax" which we would prefer to avoid. But my point is that these should be individual decisions by creators, not wholesale decisions by a publisher cartel who profits disproportionately from a very small number of high profile acts, and is keeping down the greater number of people who could benefit (consumers and lesser known artists) from a new medium.