Yup. I remember Great Debates threads with pages and pages of discussion about whether the moon landings were faked, or the 9/11 attacks were a false flag, or climate change was fake, or race-linked differences in IQ test scores were genetic, and so on. They weren’t particularly enlightening or informative, and the fact that the “contrarians” who kept them going were smugly convinced that they were bravely “daring” to “deviate from the crowd” didn’t make their arguments any less stupid.
Sometimes that can happen, but ISTM that in most cases thoughtful and articulate posters have little trouble making it clear what they’re actually trying to argue, and most of the posters who respond to them have little trouble separating out the different kinds of arguments.
Look, for example, at the recent IMHO thread on interpreting the display of American flags, where there was plenty of reasonably expressed disagreement and AFAICT no reflexive “pile-ons”, “merciless attacks” or similar disproportionate responses that tend to get whined about. Likewise, there’s been quite a lot of constructive engagement with differing viewpoints in the various Gaza-war threads, even if the one thread that was actually advocating for ethnic cleansing got (rightfully, IMHO) shut down.
It’s true that many posters with well-established track records of saying stupid shit tend to get jumped on for potentially controversial remarks before it’s been clearly established that what they’re currently saying actually is stupid shit, though.