Your description of kata’s use in karate is rather limiting, and while it may define how traditional karate approaches kata use, it is not descriptive of karate in a larger sense.
There remains an ongoing issue where trying to look at a piece of the art and using that piece to define all of the art is incorrect.
Joe Swift once defined karate periods as follows. [BTW they are just guidelines not an official categorization, and this is important because it suggests that karate is not a single definition..]
Classical Karate – roughly pre-1920. Karate was a non-documented practice and most of the kata in use today were originally formulated. The method of instruction was most individualized.
Traditional Karate – roughly post 1920 to say 1960. Where new beginning forms were created and in Japan karate training underwent structural development. During most of the period prior to WWII on Okinawa it remained Classical Karate. On both Okinawan and Japan kata continued to change for varying reasons. This is the true constant in understanding kata, it was never a fixed concept, except for the beginner.
Modern Karate – roughly post 1960. Where all the older structures really underwent change. Karate spread to the world. Okinawa in the late 50’s began adopting some of the practices that developed in Japan (uniforms, rank, formal organizations).
Contemporary Karate- Whatever occurred in the past 10 years to the Present.
Now we have some very interesting information about what Classical Karate contained. Mizuho Mutsu, an early student of Funakoshi Ginchin, was unsatisfied with his training and in 1930 traveled to Okinawa to train at the source. From that training he wrote two books.
The second book, written in 1933 Mutsu Mizuho’s ‘Karate Kempo’ (a bio of Mutsu and a description of this marvelous book can be found at http://seinenkai.com/articles/swift/art-mutsu3.html
). [This was before Funakoshi wrote his “Karate Do Koyhan – the Master Text” in 1935 and Mutsu defined almost all of the kata later included in the JKA, as opposed to Funakoshi’s choice of 15 kata.] BTW the book was reprinted in Japan in the 90’s and does cost quite a bit to own a copy, if any more are still available.
One half of his book focuses on how karate techniques may be applied, structured into type of defensive movement. He begins with bobs, weaves and dodges. It’s obvious that these techniques were part of some karate in the past. For various reasons the art does not seem to have focused on their use.
For example they present one way to deal with striking attacks, such as a boxer might use, but there are other ways to deal with those attacks without using those motions. Way using techniques in kata, perhaps with a basic Indonesian perspective, but still with kata technique.
It’s rather clear to me that Classical Karate did not share the restrictions about kata technique that have been suggested.
In effect the manner in which kata technique may be applied is almost limitless. While I make no claims for reaching that understanding, I keep working.
The limits of kata technique application being set by the interpretations preferred by the instructor or the practitioner. That many styles of karate only focus on a subset of any kata’s use does not prevent others from taking fuller advantage of those techniques.
I would suggest you should frame your discussion more appropriately to those groups of traditional karate which use the restrictions you describe.
You comments just don't describe karate as I see it.
Simply put if there isn't kata it isn't karate (of any sort).