I'd prefer more proof / context than GP gave, but I personally find it very useful to see people making judgements about AI-assistance of articles. Almost no such articles are worth my time, and the more HN people saying it, the more I know not to click past the HN headline.
Same as a NSFW tag. It's not about adding to the discussion; it's a very brief warning to users who don't want to see that kind of content, and its brevity makes it come at almost no cost to users who don't care about SFW/NSFW or AI/OC distinctions.
I agree I run the risk of being wrong and could at least provide some evidence, but I think at the very least it can be one additional piece of information someone could use in their consumption of this content.
If you can't be bothered to write even one specific thing from the article content you object to, then your account might as well be a pre-LLM bot that just posts "first" or "LLM Content" which is somehow even lazier than an LLM blog post.