Hmmm.....
I don't seem to be getting the message across. I most definitely believe that almost anyone can learn anything related to dive-theory but this thread isn't about me; it's about the standards so I'm trying to explain to the best of my limited ability how I think PADI would like you see the world. I already wrote what I see as the major problems in my previous post but at the risk of talking in circles......here we go again. There are two questions about the theory (by which we understand the "underlying" theory and not the practical application of the theory):
1) Do students need to know it?
Your response would be "Yes" but PADI says "not at first" and moreover, when you do teach it, the order of presentation is A and then B and then C. It's not about their trust in any particular individual to learn anything, it's about that PADI (and they haven't done this randomly) wants people to start diving immediately and they put their focus on in-water training and the practical application of the theory. It's a choice that grew out of the "immediate gratification" culture and PADI is very much aware that a majority of divers don't give a rat's-ass about the underlying theory, they just want to roll backwards off a boat during their holidays with the expectation of having some good safe fun.
Do *I* agree with this, personally? Yes and No. Yes I think a modular approach is fundamentally the right choice and No because I think the helicoptor level view is missing. I don't think that it's right to present the application of the theory without laying the foundations for further learning. You're learning to do things without necessarily understanding why and I think there's a risk to that. When I took OW I didn't understand the point of the mask drills. I could do it easily and it seemed pointless to me. Until on my 5th or 6th dive I got a little too close to the diver in front of me and he kicked my mask off my face. It sunk in at that moment but the "why" shouldn't come to you like that.....
One more point about the modular system: While I think the modular system works I think the tempo undermines the value you could get from it. The present system forces you to take OW, AOW, Rescue, a couple of specialties before you have the basic skill set and level of experience you need to be a self sufficient diver. (PADI would disagree). What I see is that the majority of divers never progress to Rescue and they end up spending their vacations playing "follow the leader" behind a DM because otherwise they don't feel safe. This isn't producing safe divers, if you ask me, this is producing fodder for the dive-industry. If you want to become a confident diver in the PADI system then you need to progress to Rescue, you need to put in a 100 dives and you need to be aware that 99% of your learning will be done after the course without an instructor present. This message doesn't get communicated to beginners because it would scare them away. It's something that a lot of people discover after the fact and I think it's one of the main sources of the disillusionment people have in the system. Expanding the scope of the OWD course would have a very calming effect but you'd find fewer divers getting trained. PADI chooses for a bare-bones intro because it draws the market. I think there's room for both a bare-bones OWD and a sort of OWD++ where you actually sign up for rescue and do OW, AOW and Rescue one after the other with a dozen or so guided dives more concentration on skills (especially buoyancy). I think there's a small but lucrative market for this and I think that people who took such a course would be more prone to keep diving. Alternatively raising the bar for experience requirements in response to the high tempo might be a major improvement.
2) Will knowing the underlying theory make a student a safer diver?
PADI clearly settled on No. Knowing how to *apply* the theory will make divers safer and PADI wants to produce safe divers, not necessarily knowledgable divers or even "good" divers. This is a key point. If you think it through then what you really need is the ability to apply knowledge. PADI chooses for practical in water training and you learn various skills that form the basis for safe diving. Let's say that again. You learn "skills" to make you "safe". The underlying theory doesn't factor in to safe diving as PADI sees it. If you make a safety stop you're being a safe diver. It doesn't fundamentally matter to them that you know "why" you're doing a safety stop as long as you do one. Application of theory takes priority over understanding the theory. Being able to use a table takes priority over knowing how it was developed.
) and we work in teams to train students. We're training OW through Rescue on a weekly or monthly basis all year round so if a student is struggling we can assign a personal DM to them for the skills and slow them down by letting them jump from group to group and do things over and over until they get it (this is the power of the modular system). After the course we have an active "Discover Local Diving" programme and a club that many of the new students join. The club usually has about 250 paying members from all levels so we can get beginners diving locally under supervision for the first year or so and get them networking with experienced buddies. This works out well and it comes from the organization and the commitment of those involved, all but three of whom are part-time or volunteer. Obviously not everybody opts for the club. Many just want an OW or AOW to get ready for a trip. They come and train and disappear again or they take a scuba review just before going on a trip but I'm confident that these are not the ones your shake your head at. =-) The PADI system *does* work if you use it right but it doesn't *force* you to do it right (as it were). 
