I’d like to suggest something to kick back to the developers of the forum software.
There ought to be a Thumbs Up for the overall thread, not just individual posters. That way if forum members felt a thread was particularly useful, they could effectively vote on the general usefulness of the thread itself apart from the helpfulness or likability of individual posts. In an indirect way the # of replies, the # of visits say something about a thread but the number of Thumbs Up for the thread overall would be a more direct measure, potentially, of what users think. Although maybe in deference to the OP, Thumbs Up for the overall thread would suffer “grade inflation.”