Yes, I was disappointed with Venn speaking that way. Imagine turning to a woman and saying loudly, "Well, we can't use these belts because none of them are big enough for you. And I tried all of them." (Or words to that effect.) Actually, I think it was Gunnar who did rather well in terms of customer rapport here.
I remember Christian Siriano having that difficulty with the girl, but in his defense I think part of it was his lack of experience out in the world--he was just 21 that year and had spent his teen years working in ateliers with the likes of Vivienne Westwood--and his young client's rather forceful personality. Her size wasn't as relevant as her temperament, I think.
Venn is a fashion designer for certain particular reasons, I imagine, that have to do with the beauty of the clothes themselves and of women who will wear them. I'm not sure he really thinks of designing as a service occupation, which is something you need to have or develop if you want to deal with the world. He doesn't want clients: he wants muses, the likes of Nan Kempner (who was very tall and was I think the original person who was called a "social X-ray." Or Daphne Guinness, who is both an heiress and a gorgeous clothes horse. Ordinary souls such as thee and me would (if we won the lottery) go to the likes of Rami Kashou to have a design made. His object is to make a woman beautiful with his clothes, not merely to look for the most beautiful woman to display them.
Do you remember watching the series where Austin Scarlett and Santino Rice went to different working-class communities and made a dress for a woman? It was a lovely show precisely because of that reason: that they treated each client, no matter how old or pudgy or plain, with respect. Their clients included a woman who worked on a fishing trawler and another who was in the military. In one stop, they made a dress for a middle-aged woman who was a breast cancer survivor, as was her mother, aged about 85. They ended up making a dress for the mother, too. It was a charming show, because of the way the clients were treated. I almost think it should be made required watching for any aspiring designer.