This issue comes up from time to time. I can repeat what I’ve written before. People here are posting opinions to the general public, and responding to replies that were also addressed to the public.
In fact, I wouldn’t have said here most of what I did had I been addressing the person whose comment I’m replying to. People hardly change their mind because of a petty argument. But I’m putting it out there. For this reason, once I feel that my point was sufficiently expressed I would refrain from replying to last-words, which sound, to me, like ‘Nuh Uh’. The readers have enough material to decide at this point.
That being said, there is a certain type of conversation that should be avoided, and I’ve pointed that out before when it happened. That is when indeed the conversation takes on that boy-girl giggly sound, or when it starts turning personal.