As a working DM it still surprises me that it only takes working with a few students to complete the internship part of the course. Before I got my card I helped certify over 40 students from jr ow thru rescue. I logged over 160 hours in the pool alone working with students. Not only working with them but working on my skills at the same time. It's how I learned to hold stops at 8,6, 4 and 2 feet for up to 10 minutes at a time with ease. Hovering inches above a problem student prone to panic when the instructor is demoing a skill in order to keep them from doing something stupid. How many of the DM's you see now can do this. I also took a break from it when it got too tedious and the stress of being responsible for other people every dive made it cease to be fun. It's when I really got into solo diving and then tech training to have some fun and relax and recharge. I'm now doing the crossover to YMCA AI followed by YMCA Instructor in May. I enjoy working with students again but not to the exclusion of diving just for me. That is one of the problems I see. DM's who only dive the same place, only with students, and rather than this improving their skills it may indeed have the opposite effect. How competent do they have to be to lead people who have no skills or only rudimentary ones? Many of them work with instructors who do the same dives and again while they may be good divers their own skills are often eclipsed by people they trained who have gone on to different areas whether it be tech, taking classes from a different shop/instructor/agency, or just finding a mentor or group of mentors.
In any case 20 dives is nowhere near enough to start DM. ESPECIALLY if all of those dives have been in the same conditions in the same place. WHat the 20 dives is about is money. Plain and simple. Get em taking ow, aow, rescue, and DM in as little time as possible and generate as much in the way of materials, fees, etc. It should also be a requirement that a DM have all of their own gear. I mean all of it. BC, reg, tanks, exposure suits, and back ups as well for as much of it as possible. If you have to rent your gear you are not ready to be a DM. WHile it's true that there are those for whom diving may seem second nature and may be able to start with 50 or so dives. But while doing this they should be helping out every chance they get. Once they get the cert it will pay off if they've helped with 10 or 20 students as opposed to a couple classes.
ANd dive skills need to be emphasized more. Face it anyone in relatively good shape can meet the requirements. But without requiring real experience it means nothing. And not in BS courses like fish ID, boat diver, project aware etc. A minimum number of dives in deep, night/low vis, current, navigation, search and recovery, and other courses specific to the environment most encountered need to be a part of it. Obviously if you don't have an ocean or river nearby perhaps current may not be possible but if you live up north then drysuit experience should be in there. ANd if you are going to move to a different climate then maybe some extra dives in the new place before you can assist or teach. I would not want to be watched on one of my Erie dives if the only place they've dove is in the caribbean and never dove dry. The same should go for instructors as well.