I know, seems a bit silly right? But go with me for a moment. First, I'm assuming you get the duck reference? If not, it's probably a cultural difference, but in US English, "If it walks like a duck, and talks like a duck..." is basically saying "well, treat it like a duck". or "it's a duck". Usage varies, metaphors are fluid, so it goes. I figured even if this idiom wasn't shared, the meaning still wouldn't be lost.
That aside, why? Because the normal rhetorical sticks don't really work in conversation, and definitely not short bits like comments here on HN, when it comes to asking a person to consider a different point of view. So, I try to go in a little sideways, slightly different approach in terms of comparisons or metaphors-- okay, lots of time more than slightly different-- and lots of times? more meaningful conversation and exchanges come from it than the standard form because, to respond at all, its difficult to respond in quite the same pat formulaic dismissal that is the common reflex-- mine included-- I'm not claiming perfection, only attempts at doing better.
Results vary, but I've had more good discussions come of it than bad, and heard much better and more eye-opening-- for me-- explanations of peoples' points of view when engaging in a way that is both genuine and novel. And on the more analytical end of things, this general approach, when teaching logic & analysis? It's not my full time profession, and I haven't taught in a while, but I've forced a few hundred college students to sit through my style of speechifying and rhetoricalizing, and they seem to learn better and give better answers if I don't get too mechanical and use the same form and syntax, words and phrases and idioms they've always heard.