I don't find it surprising that people send LLM-generated docs, publish LLM-generated blog posts, etc. Writing is a chore and there's this big button labeled "get it done".
But almost no one is forthcoming about it: maybe 1% of AI-generated text I see credits the tool? People deny it even when caught red-handed.
I suspect one reason is that they still want the credit for pressing the button. But another factor may be that they realize there's no moat. If person A can prompt for blog posts, so can person B and C and D... so you don't want others to get the same idea.