Then are you saying that many members here in the forum should be reported? Because the reality is we are the one who is mainly responsible for creates large-volume threads and megathreads up to the extent.
Megathreads by definition are a thread where there is a lot of replies and messages in that thread (in most of the cases are repetitive post), CMIIW. By this definition, I don' think we can blame the OP. But of course, they are irresponsible when they don't close their own thread after it has been answered. There is no harm reporting a lot of members as long as it is the right thing to do right?
I think there's nothing wrong if lots of replies are existing in a thread as long as your reply is not plagiarized at all because you are only expressing your own idea about the topic. If there is the one who made certain lapses, that would be the creator of the thread for not locking his thread after getting the answer he is searching for.
Plagiarizing is not the only thing that is violating the rules, spamming is there too. So even if you have the same idea just like the others, posting it, again and again, is a violation too. Even if it is your own idea, what's the point to say it again if somebody else already saying it? Why bother to do so?
As Welsh said, a lot of people don't even bother to read a few pages or even a few posts above them. I've seen a lot like this where a post conveys the same message like 2-3 post above it, mostly in bitcoin or altcoin discussions section and my local board.
We all know that the authors of these threads must lock their post as long as they have been answered but yes, it's still the mods duty to secure those from spamming. Then I suppose that the one who must be blame here are the authors right? They're the ones whose starting the problem for spamming and bumping.
As we can see that economics section has the most bumped threads and together with the marketplaces as second as I refer.
I think both the author and the posters should be blamed. Even if the author did a mistake, what makes those thread full of spam were literally those who keep reposting the same message over and over again.