Has Anyone Criticized The Choice Of Your Cables?

Has anyone, either a dealer or an experienced friend come over to your place and provide some constructive(or negative) critism to the choice of cables in your system? If yes, how would you deal with it? Recently I have a guy who came over and he was pretty vocal on the cables in my system. Although the choice of words were quite unpleasant, I just brushed him off in a friendly manner since I am an open-minded person. I was just wondering how one would react in these kind of situations.