:::::::::Out of a hundred image requests or submissions, I may get one question about attribution - its a pretty rare thing.  Much more often, I see "yeah, Wikipedia can use it" or some other statement that doesn't confirm the license the way we need.  If you don't wish to explain the problem up front, there's no reason you can't explain it if asked and point to the caption guideline for further information.  It looks like the discussion has been mentioned on the village pump as well, so hopefully some other viewpoints on the situation can help the discussion. 

Personally, I agree with the general usage, like I said, I think its much of the same reason that the history is a separate page and text submission isn't credited in the article either - accessibility, readability and standardization.  I don't see a compelling reason yet to change the guidelines - in this case, there was another free image available without the caption concern.  I imagine there will be cases that it would be difficult to get another free image, but in my experience, most contributors to Wikipedia are willing to abide by the policies and guidelines when someone takes the time to educate them.    babelfish