Yes, and even if a forum has very useful information that can help people, but regularly there also appear weird postings, bizarre commentaries, etc., it turns people off and readership drops.
Sometimes the very promotors or fans of a health philosophy or protocol drive people away, I can think of 4 such forums off the top of my head.
Take Iodine forums for example, there are such forums on cz, yahoo, facebook. I notice the character of the forums, and their followership / success, is based on good forum management practice. When it is a free-for-all environment, it is anarchy, and never builds momentum, or loses any it has. In driving away rational people, it also drives away many potential contributors. That's the fruit of anarchy.