Back to the question, there is one person whose replies instantly cut into any general discussion and destroy debate. Let's say (as a pure example) you put up a posting to discuss cycle touring in France..... you will get a range of replies with tips, ideas, routes, or maybe someone saying they tried it but preferred Spain. This other person will the launch in with a tone of "why the hell go there, blimey you're a thick twat" whilst quite possibly never having been there (or even been touring)
Points for guessing who!
btw just reread the text I put above, and want to make it clear that it actually IS an example!