not sure if this is why they do it, but trademark law requires you to have a generic name for your product. "Kleenex brand facial tissue" not having and using

not sure if this is why they do it, but trademark law requires you to have a generic name for your product. "Kleenex brand facial tissue" not having and using a generic name creates the danger of people attaching your trademarked name as the generic and you might lose your trademark.