I, too, took a karate class in the 90s. It was taught by a blonde Norseman, because that is who inhabited Minnesota. I don't think it was a total scam in his case, but it definitely felt less "self defense" than I would have liked. When I was a teen and joined the Young Marines (Boy Scouts with fatigues, basically) the Staff Sergeant running the show introduced us to Marine Corps LINE Drill, and there was overlap with my old Karate movements. However, there was much more of a "here is how to abuptly stop someone from being violent toward you," and less of a "follow the kata pattern," to the instruction there.