You can triangulate the issues if you look at a variety of languages. They’re linguistic taboos. In English and German they tend to be sexual or involve private biology in some way. In French they’re religious words that should be held in high regards being used in profaning ways. In Scandinavia it’s diseases one would rather not have. These are words that we set aside for some reason to not use in casual ways at one point and then we use it as an easy taboo to break