I think they're bullshit. Anyone can tell you to kick someone in the balls and run away, or buy pepper spray. Why would you pay someone to tell you that?
My opinion is more or less formed by the fact that I know someone who was ripped off by one of these courses. They taught them to aim for the junk, slap the ears and sold them pepper spray after the class ended. I also could confirm that the telegraphing of these "self-defense" moves were extremely obvious and uncoordinated, probably taught by a guy who looked and acted like the karate instructor from Napoleon Dynamite.
To be clear, I know how to defend myself. I've done judo and karate almost my whole life. I'm railing against the cashgrab throwaway courses that instill a false sense of confidence in women by teaching them impractical nonsense. Real technique takes study and repetition to develop, and that doesn't happen in 1 night at the rec center. I advocate any and all real defense or martial arts training.