A class such as tbone's would take all the fun out of diving although I am sure I could complete the skills.
why does that course take all the fun out of diving? That's all done in the pool, and who says those skills aren't fun? Remember though, these are all college kids. Which means that things like the ditch and don becomes a competition to see who can get the highest score. Things like the swim/kick become a race to see who can beat them back. The regulator drills are pretty much just rude and I don't think anyone actually likes that, but once they figure that out, they get to do stacked drills where they swap everything except their bathing suit, while buddy breathing, to a diver who is kicking on top of them while doing laps in the dive well. That does actually become quite fun. They also get quite a bit of "play" time in the pool where there is nothing in particular that they have to do, just get comfortable and do what they want to do for an hour. Practice whatever, work on trim, doesn't matter, just play time, and they get that in open water as well.
Once in the quarry for OWT, those skills have shown us that they can be trusted to basically execute dive plans on their own. First dive we have to crank out a skills checklist because NAUI says that we have to, but the next 3-4 dives are navigation dives where they only see us if something goes seriously sideways.
The buddy teams have direct supervision, but it is from above them with as little interference as possible, typically only when they violate some rule that we have, or they need some compass intervention. Even if they get hopelessly lost, we just reach down and adjust their bezel to a new bearing and they are expected to recover from that error.
They are responsible for actually going diving. VERY few divers ever get that experience in open water training which is usually just follow the instructors around. We are training self sufficient divers, if you follow the agencies courses to the T, you can't say that because the simple fact is, they don't train fully functioning divers that are capable of planning and executing their own dives with no one but their buddy. They're trained to be under some sort of supervision. We have a very low dropout rate after the class and there are quite a few that come back for many years to volunteer with the program.