I don't think you're doing anything wrong. AI-generated media is now reality, regardless of what we think about it. From that perspective, I don't even see realistic harm in an individual using Stable Diffusion commercially, undisclosed. Any competition you'd create for authors of media in the SD dataset would be a drop in the highly detailed, AI-generated ocean

You're not nudifying unsuspecting people for their stalkers, so no worries on that part

As for artistic purity, I consider cave painting the only Real form of Art. Everything else is plebian