I'm just getting around to digging through this thread, so ignore my posts if I'm repeating something already covered in the intervening 2 weeks. What you describe in the second sentence is my definition of "application" in a MA context. Perhaps part of the frustration here is a difference in usage of terms?
Looking at the way it can be used is an application. The issue I have is with the claim that the form "teaches" that application, if 90% of the application is not in the form.
We have a kick combination at my school that is a front kick followed by a 360 hook kick. Could I claim that our basic form #2, which includes a front kick, teaches you that application? No, because the 360 hook isn't in there. I can say "here's a way to follow up that front kick" but I can't claim that the form teaches it.
We have similar blocks (we call them "cross-blocks") in NGA. I've reduced to teaching only one of them (originally there were 4) because I don't see them as all that beneficial. However, in extreme cases (caught off guard, can't shift out of the way of a power strike, so have to go force-on-force), they have potential application. I don't think the application gets much deeper than that, unless you look for non-blocking uses.
Something to consider: maybe some of the techniques in forms are - as you start to ponder at the end of this post - for building movement, rather than direct application. If I can get you to successfully move your arms in different operations at the same time, your ability to deal with combination attacks probably improves. And it's a harder thing to do, so I'm helping build your overall movement ability, which is good for you, even if there's no direct application.
This is one of the theories I had, and I wanted to see if anyone else came up with the same idea - that the double blocks are more about teaching you to focus on both hands instead of just one.
The one I hear is "practice doesn't make perfect, practice makes permanent." (Although usually that's followed with "perfect practice makes perfect").
I have to say I disagree, PDG. As an instructor, I don't want my students to have to rediscover anything important entirely on their own. I want to teach them to discover, but I want them to be able to make more progress than I did, so I provide them some help (sometimes answers, sometimes just clues). So, if I were teaching TKD and had any idea what the purpose of that chamber was, I'd teach it. I might not teach it to beginners, but once they've got that basic movement down, it's time to give them some purpose to a chamber that really doesn't serve a purpose in live use (you need to keep that guard up, so the chamber can't be fully used). And if the motion of the block has other uses, I want to introduce some of them.
Why take away that early discovery? Because if I give them a better start than I had, they can develop better skill in some areas than I could. And that's always my goal as an instructor: help them find something they can do better than me.
This is basically why humans have dominated the planet. It also shows up in monkeys and dolphins. The ability to pass down knowledge is how we make progress. Sometimes you want people to critically think about things and sometimes you want people to come up with their own answers.
The accuracy that Taekwondo aims for in the forms suggests to me that at the very least, there are specific reasons why those motions are used. If there wasn't a reason to do it the way it's done, then it wouldn't matter if you vary the form to fit yourself. Now that's not to say you can't go on and find your own applications. But someone doesn't demand you copy their moves exactly, without having a reason to copy those moves exactly. Just like in Karate Kid, when Daniel started on any of the chores, and Mr. Miyagi corrected the way he was waxing, sanding, or painting. He had a specific reason for Daniel to do the chores in the motions that he used, and that reason became apparent when he showed Daniel the application. So it seems to me if we're training this way, there's an answer, and not a discovery as to why we are.
(As an aside, I've always been bad at riddles that are just all metaphors. You have to know what the metaphor the riddler is using in order to guess the riddle, and not being psychic I could never figure those out. This may be part of why I have more of an issue than others with "here is a motion, figure out how it is used").
There's a guy I used to work with that had the attitude of "I had to figure everything out when I started here and nobody helped me, so if you want to be good at this job, you need to figure things out for yourself." I butted heads with him a lot, because every time I'd go to him for advice he'd make me feel like an idiot for not knowing things. I, on the other hand, write a white paper any time I figure something out that would be useful for multiple people, because I'd rather they didn't have to spend the extra time trying to figure out something that we as a team should already know.
I get that you have to give people room to discover and explore, but that doesn't mean that's ALL you give them. You have to give some guidance, and sometimes if someone is stuck on something, you just have to give them the answer and move on.