Why is unrealistic “Bunkai” being taught?
.
The answer is simple: Because the vast majority of karate is taught by instructors who don’t know what realistic bunkai is. And that’s because their instructors were never taught it. And their instructors’ instructors were never taught it.
.
The original creators of each kata had their own applications which, according to oral histories, they did teach to their top students (not all of their students, by the way). However, the transmission of that was incomplete and eventually faded away in pretty much all lineages of karate. No karate instructor these days can definitively say what each technique in their kata was originally designed to do. However, we can guess, reverse engineer, work it out for ourselves.
.
So if we can work it out for ourselves why then is most bunkai unrealistic? ……..Perhaps there is another answer: Children.
.
Children are not taught effective bunkai because it was not part of their curriculum. So, a question arose; “If we’re not going to teach them true bunkai, what will we teach them?”
.
What is taught is a “visual” method. If it looks like a “block”, it’s a “block”, if it looks like a “punch”, it’s a “punch” etc ….. That’s all they need to know. In this phase of their training, you just get the child to DO the technique. Hopefully as they get older, the next phase of their training is to get them to UNDERSTAND the technique……… And therein lies the catch-22.
.
The Japanese have terms for this concept: “Bunkai Omote” (obvious, surface), “Bunkai Ura” (hidden, secret, or alternative), “Bunkai Honto” (real, or true). What we start out teaching children (and perhaps beginner adults) is the “Bunkai Omote”, because it’s obvious and simple.
.
That child grows up never being taught the true bunkai. Either his school doesn’t have the instructors who can pass on that knowledge, or, he has already become the instructor who was taught the visual method. What the child knows becomes myth, and that myth gets passed on.
.
“My instructor taught me that, so that must be the case!” He will eventually become an instructor who believes that is what the bunkai is all about, and thus perpetuates the myth.
.
In some schools, children may be taught that visual method and later, if they stick around, will be taught the ura bunkai……And if he doesn’t, he loses out on that knowledge, or, he perpetuates it by starting his own school, or joins with another with the same background.
.
This explains why there are some schools that teach it properly, and why there are some schools that just don’t get it. They’re all just stories we teach kids because they’re good visual aids.
.
Those schools who focus mainly on competition and sparring, the bunkai omote is all that you get. And for those in that style or brand of school, that is all that they need to know. They’ll never apply any kind of bunkai; omote, ura, or honto – why? Because it’s all they need, it’s just not part of their curriculum. 
.