Does that mean that everyone who wrote a post in that thread are regular sig spammers? If you go looking for such illogicalities, you will find them in at least 30% (probably more) of the topics in the Bitcoin discussion and in other boards. I won't say that it's not problematic, but I focused more on the fight against plagiarism, AI and on low value topics in that board and I definitely missed this.
I was one of those who thought that where you are supposed to try to take care of the quality of the posts, at least the people who write on page 1 should read the OP carefully and the subsequent posts before writing theirs but I dismissed it as mission impossible a while ago.
When you find someone who doesn't seem to have read what was written in the OP - then you can report it to the moderator. Your job is only to submit report and you can never decide whether it is worth deleting or ignoring. Regardless of what the moderator decides about the post you report - your job is only to report it.
In any case, what I report is up to me. And as Alone055 says the problem is that in these cases they have skimmed through the text, so what they respond to has something to with the topic so they are not completely off topic.