self protection? Just kidding. I think it's part of self defense, but just a very minor part. I'm not convinced that a black belt in BJJ is any more likely to keep you safe than training for a tough mudder competition. I've said this before. We have no data to support that training in a martial art will make you less likely to be attacked than someone who trains in Tai Bo or Parkour. Further, there is no data to support the idea that someone who trains in BJJ, MMA, RBSD or whatever it is that the self defense guys here teach, will be more likely to survive an encounter than someone who trains in Tae Bo or Parkour. We know that few people are attacked, and of those, it is exceedingly unlikely you will be killed. And that's if you do everything wrong.
If you're a cop or a soldier, sure. You need specialized training. But the average citizen, who has no venue to apply the training to actually develop practical skills? I'm skeptical.
Simply put, I think there is a physical element to self defense, but that its relative importance is low compared to everything else. Unless of course, you define self defense differently, which is fine.