On the LA board today, someone has posted several responses to comments made to year-old (or longer) posts. Mostly, the new comments are very brief and add little to the discussion. But until you open the post, there is no way to realize that the first 10 posts in the thread are extemely old.
Isn't there some way to set a limit on responding to old threads? If someone has something significant to say about a place, there's nothing wrong with starting a new thread. But bumping up an ancient thread to tack on an "I agree" or "I disagree" doesn't help readers that much.