There's a feeling of disgust that people have. Its ancient origin is anchored to things like smells and tastes, and it protects the organism. We haven't evolved any new hardware. What we have built in terms of our morality norms, and our sense of their violation, is anchored to this same circuitry. "Disgust" is doing a lot of work in the moral domain, and the political domain. Based on culture, this can play out in very different ways. There are cultures that eat dogs, and we find this absolutely disgusting. Many of us eat cows, and the Hindus find this disgusting and sacrilegious. Clearly, to talk about the ultimate wrongness of eating cows or dogs, the conversation can't begin and end at what people find disgusting.
In a person's capacity to be offended, the feeling of offense is not an argument, and it's not a virtue. We all have this thing, and in many people, is functioning like some kind of epistemological principle: "this is how I'm going to judge the correctness of a view. I'm going to react to it, instantly." So if I say to you, "Well, there's good reason to believe that men and women differ biologically. Start with the uterus and start counting from there, and the more science studies our differences, we have discovered that this extends to human psychology, cognitive abilities, and interests." Once you start linking those sentences together, people begin to get uncomfortable. The discomfort isn't evidence of anything... It's a logical error to move from the feeling of "I don't like the way this sounds" to "this feeling counts as evidence against the view."