We are living in a time of "know it all's" because its so easy to challenge other people's opinions without meaningful discussion on the web. One thing I find that does "dis-arm" rude responses is using "personal opinionated phrases":
"It's been my experience that there are no major differences between affordable vs expensive cables"
VS " Stop buying the snake oil, there are no scientific evidence that cables make a difference"
I believe Online forums, twitter, etc has eliminated educated discussions among people on any topic.