Caveat: All the following is my own opinion, based on personal experience and study ... a mis-spent youth, 33+ years of budo, time spent as a cop and Soldier and involvement in studying and teaching both self deense and close quarters combat. YMMV, of course, and there are ALWAYS exceptions to any rule.

For basic personal protection, training diligently in a few techniques, that become well-drilled and integrated, is pretty much all most folks will ever need. This does not apply to those for whom imminent violence is part of their lifestyle or career choices.

By far, unless you're in a third-world (yeah, I know that's not PC anymore) or combat-zone locales, you're not going to NEED fighting skills.

Outside those sorts of places or a career in a violence-related profession, self protection (vice self defense), in terms of situational awareness, staying out of bad places and away from bad people and taking care of your personal security are mostly all that will ever be needed.

As I said above, there are exceptions, but, if an average person, living in a reasonably civilized locale has to engage in serious violence, something's probably gone very wrong. Fortunately, those situations tend to be few and far between.

For most people -- who are not cops, soldiers or otherwise engaged in a job field requiring proximity to and involvement in violent conflict -- a few well-trained techniques are all that are necessary ... and those will be used to resist and escape, not to stand there and fight. And they should be deployed only in extremis.

To me, what is far more important than teaching self-defense, is teaching personal security.

Personal protection and security, vs self dfense, means teaching situational awareness, common sense home, auto and personal security, recognition of potentially bad situations, etc.

It means teaching people to be aware of their actions, to be cognizant of their surroundings, to be proactive in terms of Not Getting Into Trouble, in the first place.

It means teaching people to lock doors, secure windows, not leave Rolexes lying about on the dashboard, how to carry a handbag or rucksack (and not to carry anything that you can't stand to abandon and flee), not to get so wrapped up in your cel phone or text message that you fail to see the buss barreling down the street ...

It means raising awareness of how clothing and footwear affect your ability to fight and flee (and that the flight part is FAR more important to Real World personal safety and security than fighting skills).

IF, and that's a big X-factor, Joe Average has to engage in personal violence, chances are, things have gone tits-up and all the personal security and safety preparations have failed anyway and he's going to be fighting for his life.