Good question
I make the optimistic assumption that if nobody replies to a thread, that at least people have read it. Having everyone post the equivalent of "hear, hear!" is counterproductive, and if nobody responds, one can assume that either nobody disagreed, that people disagreed but didn't think it was worth the effort to post a disagreement, that people thought it was out of their area of knowledge (the main reason I stay out of geological arguments), or possibly many other things. Don't read too much into orphan threads.