Perhaps the problem is that the watermark itself does not function as a link? If the platform wanted to, it could treat any "registered" watermark as a link to the original poster on that same platform. This wouldn't help when the watermark gets cropped or scrambled, but that's more work... maybe there is room in the jpeg file for an "invisible" canonical link to be encoded? If not then future image formats should totally do this.
The problem is that "curators" like FJ will just crop out the watermark.
That's what makes these accounts so uniquely infuriating. They're not accidentally omitting credit out of laziness or ignorance. They do extra work to make sure the original creator gets cut out of the loop.
