There are two things that baffle me that are an offshoot of this subject. One is a thread that starts on a subject, gets a number (you pick the number of replies) and then goes sideways with some goofy side responses back and forth in an attempt to be humorous. They get piled on and I lose interest. Then more closely related to this will be a thread that is active where it’s a year old and one person decides to respond to it. I assume that’s what is meant when maybe a new member likes the subject and wanted to post not realizing there has been no activity in ages. I just ignore the thread in both cases so I guess that I am just doing my own filtering.
I like the idea in anything of continuous improvement however that may look in relation to the OP’s original post.
One of the best things about forums imo is the organic way new topics are started - as there seems to be a need.
Some forum have rules about this; requiring new members to search for the topic they are interested in posting about and resurrecting an existing topic. New forum users are not good at searches (and the search tools rot) and I have seen them penalized for "circumventing" these sort of rules. It's a real disservice to new user imo, but the reason some newbies post to old threads. Other times they can't figure out how to post a new thread but can figure out how to reply.
It seems to me that if a topic has been languishing for a while and it's great to start a new version of the topic. There will be new opinions offered up. Interesting discussion and lots of it is what fuels forums.