My eldest son can do middling-advanced physics. But he couldn't help my eldest daughter with freshman level High School geometry last night. He could solve the problems but couldn't teach the steps to do it.
You don't have to be a USPSA grand master to teach self-defense with a firearm. And if you are, it doesn't mean you'd be a good instructor.
Doing is one thing. Being able to
teach it is an entirely different skill-set.
I've been in classes where I was undoubtedly faster and more accurate than the instructor, but I learned valuable things from them, nonetheless. I've also been mopped up by USPSA guys, who - when asked for any tips - just kind of stammered and couldn't really explain how or why they are
so damn good.
In addition to this much of lethal force doctrine is mental, and legal, and neither can really be effectively learned by putting rounds down range. Engaging targets is 100% different than knowing when it is appropriate, and what the ramifications are, from engaging them.
When I first started getting my instructor credentials, 9/10ths of my class in the rifle course were SWAT, law enforcement, and many had military backgrounds. I actually started out feeling strongly that I was in the wrong place, until later in the course, when I realized many of these guys were seriously struggling with the instruction part, because they had the wrong mindset for civilian training.
Law Enforcement and Military backgrounds don't guarantee a good instructor, any more than being a USPSA grand master would. The mindset for both Law Enforcement and (especially) Military is VASTLY different from the mindset required for civilian lethal force instruction. The rules of engagement, strategies, and tactics for both are different than you have as a civilian. Law Enforcement has the power of arrest and backup on their side, you do not. Military is authorized by our Government to engage hostiles in situations that we would never be able to (generally, from a distance, and generally, by complete surprise; neither of which are applicable for us civvies).
While a good curriculum vitae can be formed with either or both LEO and Military experience, neither are specific requirements for good instructors, and many of the reasons that would make someone a good cop or soldier just simply don't apply to civilian training.
I know I'm off the original thread topic a little here, so I'll bring it back in line.
Good instruction for lethal force and self-defense gives you expert witnesses to call on if you find yourself in front of a jury - your instructors. They can testify that various key points of ethics, morality, and law were covered in their classes, and that you passed your examination(s).
The alternative? "Well, I umm.. I read about how to shoot people legally on the internet".
One of these is a better option than the other one.