So what does all of this mean for the client? Let's say for instance that you hired Eyesometry to shoot your wedding. Part of what we offer clients are digital files that can be downloaded from a website.
This is a ridiculous example. Wedding photographers are usually paid in advance or make delivery conditional on payment. Some of them assert copyright ownership, but usually those contracts are full of holes, and a court is likely to find that the photographs constitute a work-for-hire made at the request of the wedding couple. In any case, few people outside of the couple getting married and their friends and relatives are interested in copying and reproducing the wedding photographs, so the writer of this piece is not forgoing any significant amount of income by making the pictures available under a CC license.
Now consider the situation where a picture has significant artistic, news, or entertainment value, and multiple commercial publishers would like to use the image for product packaging/advertising/art prints/newspaper features/magazine covers. That's where the real money is in commercial photography, and that's where copyright law is meant to protect the interests of the creator. I don't see any reason why the photographer/artist shouldn't enjoy a temporary monopoly because they have actually created something brand new but have considerable difficulty in controlling post-sale distribution. What good is his creative commons license going to provide if every commercial publisher can just reuse the photograph without paying anything to Eyesometry? One reason that wedding photography costs an eye-watering average of $1000 for half a day is that it's actually very hard to make a living doing stock or news or fashion photography.