Look. In 99 cases out of 100, it is plain when someone is posting in good will, attempting to originate or further relevant dialog (even irrelevant, as I so often am guilty of) on an online forum. In the other 1/100 of cases, it is equally plain when someone is posting out of obvious intent to stir shit and inflame other posters and in general throw jellied gasoline around, without any remotest interest in inciting genuine discourse about this or that topic.
Even when threads veer into the most incendiary insults of one poster toward another, it is more than clear when posts are staying on-topic.
Some of the threads referenced directly or indirectly above have been blatantly obvious attempts to poison this forum with topic-less invective and sewage. This is 'intuitively obvious,' as the more enlightened logicians like to say.
'A thing is what it is, and not something else.' -- Wittgenstein.