Besides being a catalogue of techniques, I find that kata and kihon have helped with my motor coordination and concentration. In class, we often practice 3, 4, 5 technique block/punch/kick combos while moving. Having to remember to execute the correct techniques, in the correct order, quickly, and using good form really builds your concentration and hand-eye coordination.
Another view of this kata question is:
There are students who rely on 'spoon feeding' of a TMA, and students who study the material being 'fed' to them from a basic view of human movement, then go from there with their own individual understanding.
People are different and surely they have their own ideas of what concepts/principles they need to adopt, of what works for them and more important what has been proven to work in general given the physical and mental nuances of self protection.
But there is one basic common denominator that cannot be denied, and it is the science of human movement.
It pays to understand that _to begin with _In order for the body to produce movement; the groups of muscles have to work in synergy, like they were chains. If one link is weak…well_
I have seen students coming to the dojo with inefficient body mechanics, weak muscular structure,either genetically, or because the student has not tested those mechanics through some sort of demanding sport.
A good teacher will soon realize that feeding techniques to someone who will attempt to perform them with inefficient body mechanics_ increases the danger of injury to the student and others he may work with. We have all seen this.
However the good teacher will also know that the human body can be reprogrammed, to a certain extent_ through specific methods of exercises of the style he studies and teaches, based on past experience.
The human body is capable of a great number of movements with freedom of articulation, but some people are affected with inhibited degrees of freedom and coordination in their movements.
You know it as soon as you see these people step on the dojo floor. You as the teacher will know it, but the student may not initially be aware of his own limitations.
So what I have observed over the years is that a well 'designed' kata, helps the student with such deficiencies , in exploring all the degrees of freedom in his body in order to get 'acquainted' and overcome his limitations of movement so that he can then proceed unhindered in learning specific movement patterns that lead to specific defensive applications.
At the very basic, we need to look at kata as a set of biomechanical exercises that compound movement's efficiency down the road_ when put to combat practical use .
A long term student of a traditional martial art, will come to understand and appreciate that the kata practice achieves powerful and stable ways of moving the human body in addition to 'educating' the body in power generation.
One of the reasons why I have generally seen kata champions also excel in free fighting competitions.
Think of kata as 'compulsories' in a given sport.