This brings up a great point. Why does Google not just extract whatever information Pinterest is providing and provide that directly in Google Images as SERP? If none of the content in Pinterest is original, what value are they providing the user?
Pinterest is the "experts-exchange.com" of digital imagery, except EE at least had (gated) original content.
They're providing negative value by stropping the context from stolen images and repackaging them into mindless streams and ensuring that you can't get to the images without signing up.
Pinterest (re)hosts the images so I'm not sure what you're suggesting. That Google write custom logic that supposedly unrolls this indirection on this one site where the image sources already exist on other sites?
The website the image was stripped from isn't even indexed.
But well put: If google wants to pretend it is quality material because it sits on a giant content farm they should indeed credit the original source for it. If they cant find it it should not be listed.
If it was text the entire content farm would be erased from the index indefinitely.
And this is the key point. By removing Pinterest from the search results the user doesn't lose almost anything.