The way that I see it, in general, forms can be used in a few ways:
- For physical purposes, such as exercise, to build strength and flexibility, coordination and balance, etc.
- To directly teach techniques and concepts to students
- To catalog techniques and concepts for future instructors to ensure a preservation of the curriculum
- To build muscle memory in techniques and concepts to be used later
- To be used as a building-off point for experimentation and variation that students can use to apply the techniques
Now, a lot of the people suggesting that a down block isn't just a down block, it's a down block, grab, and sweep, are suggesting that the forms are being used like the 5th point above. Where the forms are taught, and then gone back on to explore how the techniques in the form can be used in combination with each other and in combination with other techniques in order to teach a greater number of concepts.
I don't disagree that this is a good teaching method, and I don't disagree that schools do this with some of the basic techniques in the forms. While we don't explicitly state it, the stances and blocks we use in our self defense come from our forms.
However, there are a lot of blocks we use in the forms, which are not expanded on in our self defense. For the most part, every single-hand block we use will come up. We use the knife-hand block, outside block, inside block, high block, down block, and palm blocks in our self defense. We even use the combo inside/outside block from Keumgang and the low X-block and high X-block (not sure if they come from the other Palgwe forms but they're in our Palgwe 7). So in this sense, I can see that the techniques are being applied in this way.
But it is not universal. Scissor block, double-knife hand block, augmented outside block, double outside block (the first technique after the kiyhap in Keumgang), double low block (the next technique in Keumgang), diamond low block and diamond middle block (the crane stance block in Keumgang and the first part of the combo in Taebaek)...none of these are used.
There's also the weird case with some of these that the cart comes before the horse. For example, we use the X blocks in our orange belt curriculum, but they don't come into a form until high red belt (usually 2 years later). We teach the basic chop as low as purple belt, but it doesn't show up in a form until red belt.
So while our beginner and intermediate forms seem to be used in this way, where the stances and the basic blocks are used in combination with other techniques, the advanced forms don't appear to follow this mold. Once you get to blue belt, the majority of the new techniques in each form don't really show up outside of the form.
I could take 95% of the techniques in our first 8 forms (5 kibons and 3 palgwes) and use them as the start of a combo, or as a prominent piece of a combo. It drops significantly for any of the forms after that.
The problem here is that most of these other pieces aren't in the forms.
That's not to say they can't be taught and then combined with what's in the forms. But you can't say that the application comes from the forms, when you have to add a lot to what the forms teach in order to make the application work.