All agencies have some form of quality assurance in place and it's mostly passive. That is, they don't go out and watch every instructor but rather rely on reports from others. There might be a short question or questionnaire given to a student after the certification, but that's as active as it gets. To suggest that this is "monitoring" an instructor is giving the concept only lip service. Monitoring is an active process and should become interactive/invasive when a problem is discovered. Most of the agencies' Q&A programs simply react to complaints about their instructors. In other words, non professionals are the ones reporting instructors and that's often after an accident or near accident has occurred Even then, there is often a lack of resources for agencies to adequately ascertain what actually happened and these inquiries frequently turn into "he said, she said" issues with no clear remedy. To clarify further: I monitor my students during training. I evaluate how they dive and help them to change to become excellent divers. After the class, it's impossible for me to monitor them. I will still mentor them and I will read their dive reports. That's simply not monitoring them.
In your earlier statement, you suggested that NAUI monitored ALL actions by their instructors. That is just plain false and I am surprised you haven't redacted that statement. In fact, the majority of the actions that NAUI monitors, if you can call it that, are merely the ones reported by students who really don't have a clue about what is or is not appropriate. Insurance companies are more interested in actual claims than lip service to some flawed monitoring system. This is true for all agencies and not just NAUI. Unfortunately, you are more than willing to paint a single agency as being evil and the others, having the same kind of Q&A system as somehow being noble and responsible. We get that you hate PADI with a vengeance, and many of us wonder when you'll stop beating that friggin' drum so hard.
Let's face it, almost every sport has evolved to become easier and safer. Look at football for example. The helmets have evolved just as the pads, the shoes and everything else you see out on the field. Even the rules have evolved and to what end? To make the game safer. Dive training is no different. Take buddy breathing. It used to be that octos were not universal. Your buddy may or may not have one. Heck, they might not even have a pressure gauge! My first reg didn't have an octo or a pressure gauge on it. Buddy breathing was an essential part of being able to dive safely especially if you had accidentally popped your j-valve down. In reality, almost every dive ended with some sort of CESA because we routinely ran out of air. Fortunately, Scuba has evolved significantly since the 60's. The gear has really evolved and most of the agencies have followed suit, albeit less aggressively. I can't remember seeing a reg in the past ten years without an octo. Why on earth should that be mandated standards? It's not. However, some instructors see a value in buddy breathing. All my students do this horizontally in the pool and it helps them relax and helps them to control their breathing. It fits my teaching style, so I use it but it should never be mandatory. Not everyone teaches like me. Like football, we have a few people so in love with their concept of what the sport was like "back then", that they refuse to accept the inevitable progress. They use words and concepts like dummied down to describe the current situation. In reality, the real dummies are the ones who refuse to evolve with everyone else.
I'll say this again... there is a bigger difference between instructors of the same agency then there exists between agencies. That's a monitoring fail by anyone's definition. Every agency has it's good points and it's bad points. While you want to say that these are written in their standards, I contend that they are actually their instructors. I don't care what agency an instructor teaches for as long as they are fun, safe, thorough and not burned out. A good instructor will make sure that you have all you need to dive safely and have fun. A great instructor will inspire you to excellence. A mediocre instructor is only concerned with standards and could care less if you are able to dive much less have any fun while doing it.