Many discuss and teach techniques and get down on this person or that person for not doing a technique 'as the founder taught' when, in fact, the founder may have taught them in that way because that is the way they needed to be taught in order to learn it for themselves.
In the end it is more about mechanics that absolutes, and most times the mechanics themselves have become flawed due to laziness, human error, ect.
I remember learning the fine points of Kata from my Sensei, spending an entire class on a single movement just to get everything correct, right down to the timing and rhythm within the movement itself.
If it were only about learning a technique in a textbook of techniques then this would not be necessary, only learning the mechanics would matter, so even the idea of it being about mechanics is not entirely true.
I would go through and feel as though it were correct only to have to go through the sequence again, 'No,' he would say, 'like this!'
There is a reason for everything.
It is not about learning a bazillion techniques to counter a bazillion attacks, which is impossible, more about learning what lay beneath... Physically, mentally, emotionally, and rhythmically.
It is more about the idea, the concept, than some concrete thing.
Certainly one can escape from a headlock in a hundred different ways, but there is one way that works extremely well for you, why bother with the rest?? Maybe two more, just for variation on the one, but it still goes back to that one.
In Kata there is Shuto, but the mechanics are no different than a Gedan Barai to the side, just sweeping downward with a closed fist rather than an open hand, really does not matter, the principles, the mechanics, the rhythm, it is all the same.
An Art is really nothing more than a Strategy with Tactics built around that Strategy in such a way as to allow for many ways to a single end, but utilizing the most direct means, which are nothing more than variations off of maybe six tactics (movements segments rather than individual techniques).
In Goju Ryu we have a core of twelve Kata, two of which are for training internal principles, including body mechanics, the rest are simply applying these principles and are actually variations on, again, maybe six actual movement segments.
When things become down and dirty and all bets are off the stylistic nature of the training is left behind and the principles/concepts themselves take over in a more fluid and direct manner, the true nature of the beast is revealed.
People tend to forget this when they speak of usefulness and uselessness because they have not looked deeper into things, they only see the superficial.
Sensei once said that the journey was like driving in the dark with no headlights, but trusting... For what that is worth, it has been a long journey, and continues to confuse and confound.