One point not mentioned yet... student animosity.
I am an inhouse firearms instructor for a police agency. Over the years I have had many opportunities to impart wisdom and sage advice to those I have been entrusted to train. Unfortunatly many of those individuals are quite displeased that they have to spend THEIR time off learning about STUPID tactics and wasting valuable sleep/beer drinking time with punching holes in cardboard AND then having to CLEAN the pistol. By god they will show up and simply bang the rounds down range to get it over with as fast as possible.
Sad but true.
Another point, the approved lesson plan (LP). My job REQUIRES me to teach to the standards based on approved agency LPs. Even when such LPs have some flaws. Flaws that can be corrected BUT must first go through a multi level approval process. Until it is changed the standard LP must still be taught. Did I mention that our big wig training gurus often rewrite the LPs so that we have to make sure what we teach is the most current info. As well as check it for flaws that might have slipped through.
Last but not least is the liability issue. My employers have a terrible fear of liability and have based all such training standards and LPs on minimizing such exposure. I for example, when running officers through the "official" qualification course, can NOT count any hits on target past the minimum. We fire 50 rounds "at" the target but I have to stop counting when I find 40 hits (80%). They then get a "P" (pass) and I am off to the next target to score. It does not matter if we have a rathole in the middle of the target or a pattern that covers the entire sillohouette. We teach to a level of mediocracy and actively avoid trying to get people to a higher standard to keep the in house lawyers happy.
Many officers try to get as much out of the training as possible. Looking for opportunities to improve so they might be better prepared for what might happen. They make showing up for class a blessing and keep me enthusiastic about my collateral duty. On the other hand we have some that truly do ONLY the minimum required and complain about that as well.
I hope those instructors that teach for profit appreciate the fact that people paying for training will most likely want to be there which is a great way to start to a class.