I doubt there are any perfect analogies. The point is that the more people sending off images for free, and the more organizations that usually pay to have those images, the less they need to pay in order to get those images. The less they pay, the harder it is to make a living as a photographer. And I'm not really talking about amateurs. I'm talking about advanced hobbyist who can and does take good images, but they give them away for vanity or ego.
That's clearly true. Let me make my point a bit more directly.
If all that you, as a professional photographer, had to offer your clients was mastery of the arcane art of making images using silver halides and various toxic chemicals, and the advent of digital photography has rendered that art obsolete, then you have no longer have anything to offer your clients. (Please don't take my use of "you" as relating to you personally, or of "all" as denigrating the art.)
Of course, a good professional photographer offered far more than that: vision, artistic as well as technical ability and so on. He has skills which remain of use, skills which advanced hobbyists don't have.
The need to cope with advances in understanding or technology isn't confined to photography, of course. Take an example from medicine. For much of the last century, peptic ulceration was a scourge of the Western world, with significant morbidity and mortality. General surgeons spent huge amounts of time operating not only to fix the acute complications, such as perforation and bleeding, but also in an attempt to cure the condition. Operations varied from removing that part of the stomach thought to be responsible for producing acid to cutting the nerves which controlled that production. They worked, to a degree, but inflicted their own mortality and morbidity. Then came H2 blockers, which lowered acid production. Then the proton pump inhibitors, which pretty much abolished acid production. Then came the realisation that most peptic ulceration was a complication of bacterial infection and could be cured by antibiotics. As a result, surgery for peptic ulceration has virtually disappeared. The job formerly done by surgeons is now done by physicians, without making holes in their patients. So general surgeons have had to move on, refining their techniques and offering their patients better operations for other conditions. They still work; they still earn a living.
Tempora mutantur, nos et mutamur in illis.
Jeremy
