II think there's a few key differences there.

• Writing an angry blog post has a much lower barrier of entry than learning to realistically photoshop a naked body on someone's face. A true (or false) allegation can be made with poor grammar, but a poor Photoshop job serves as evidence against what it alleges.
• While a blog post functions as a claim to spread slander, an AI-generated image might be taken as evidence of a slanderous claim, or the implication is one (especially considering how sexually repressed countries like the US are).

I struggle to find a good text analogy for what Grok is doing with its zero-cost, rapid-fire CSAM generation...