Likewise, it makes as little sense to slap down a less-well-thought-out theory as it would to slap down someone who is just in the process of learning a complex language. You come to learn language by using it, just as you tend to learn useful things by pursuing a thoughtful line of inquiry to its eventual conclusion - even if that conclusion ultimately contradicts the original theory.
Likewise, there is often something useful to be gained even from (sometimes especially from) a person who holds the most naive perspective on a given topic, and there is value to everyone in letting that person pursue their thought. Consequently, in my view, the poster who presents what in the card game Bridge is called a shut-out bid ultimately does a disservice to everyone.
To my way of thinking, anyone who casts themselves as a debunker has already concluded that their perspective is and must be the correct perspective. In that case, why bother to join a discussion group?