Deeply my opinion only:
I think you take it too emotionally. This is the essence of human society.
And sometimes truth come from wrong answers... thru the discussion.
My personal way, if i really want to, i just tell why this answer is wrong or correct one. The main thing is to be convincing in your reply, why wrong, to those who read.
If we stop turning blind eye to such bs, those who seek attention will stop doing so, because otherwise they will quickly gain bad reputation.
Sometimes people are very stubborn and you need to make it new level. Dave does that very well, polite and convincing.
I go to "russian mode", and if person keep spewing total bullshit, i tell straight he is uneducated moron, etc, etc, and underscore why, all his bs.
Yes, it makes enemies, but sometimes it is necessary to eliminate exceptionally persistent people spewing pseudo-scientific bullshit. Because they tend to form cults around them, like "flat earthers", "infinite energy generators", "perpetuum mobilers" and so on, and their stuff start to hurt society.