If they seem that way, I advise that you look carefully at the examples of activities and attitudes of people who have quit newsgroups. They were also discouraged . Though few in number, their irrational zeal drives them in their mission , so that it seems there are more of them than they actually are. By noting what happened to alt.fan.art-bell, don't allow your newsgroup to lack activity by those who find your subject valuable. It's a good idea to point those patterns out.
Linear time is a reality, but only a reality.
Explaining statistical results is fruitless. Even if they witnessed the levitation of a large building, they would swear it did not happen, but that they, themselves, had been hypnotized. They do not prolong such discussion. One practical result of such discussion is to eliminate the discussion more quickly, unclogging your respective newsgroup early. People who post to alt.paranormal and similar newsgroups, with opposing views, do so for many reasons, some mixed.