Maybe that feature when you start a new thread that asks if the topic has already been discussed is discouraging more new threads. It gives the impression that we don't want multiple threads about the same topic. Maybe we don't, but some of the threads are years old and could be discussed again, as things change and the people discussing them change too. New members may just research an old topic instead of bringing up a discussion with a new thread.
That's an interesting viewpoint, Al. I don't even notice that notice anymore. But you may be right. So, I've turned of that notice feature. Similar Threads will no longer appear when someone is writing a new topic, but they will continue to appear when reading topics.