Adhering to legal and copyright standards isn't a "cop-out"
I understand that OpenAI et al would like to assure all their investors and customers that there's nothing legally problematic with using an AI to launder away copyright infrigement, but we're going to need a few lawsuits to have the matter settled.
It is completely reasonable for Valve to forbid this until it is sorted out. Keep mind they are a company of IP creators, creating a marketplace for IP creators. The whole reason Steam was created was to establish a DRM that fought the piracy of Half Life. I am on the side of Valve in this.
Imagine taking a really dumb gig worker, showing him 10000 images, some of them with watermarks, and then telling him "draw a red car, kinda like the kind of images you saw". There's a decent chance you'll get a red car that looks nothing like any cars with the data set (original work), and yet he'll paint a memorable watermark on top because so many examples contained it, you said "kinda like the kind of images you saw", and he doesn't understand that the watermark isn't meant to be part of the picture. I believe that's whats happening.
It’s entirely possible for a diffusion model to produce an original work and yet still hallucinate a ‘shutterstock’ watermark onto it, in much the same way as GPT can hallucinate valid-looking citations for legal cases that never happened.
Producing (distorted) copies of images in the training data takes some real effort, and typically only occurs for images which are heavily repeated in the training data... Most of the complaints along these lines can be compared to complaints that cars cause massive bodily harm if you steer them into lightposts: The problem is easily preventable by not driving into a lightpost.
If this is true, then ordinary copyright law means that AI-generated media cannot be used unless you have a release from every bit of training data you used. At least some of the currently existing AI:s were trained with datasets for which such releases are impossible, so they should not be used.
Also, for the love of god, do not use any of the AI coding assistants, or if you do, at least never publicly admit you do.
This should apply to humans as well then because brains ultimately do the exact same thing. Nobody creates art in a vaccuum.