A combative martial art is a discipline and, as such, can be used as a method of culminating strength, control, and inner peace. Still, let us not forget that the primary purpose of a martial art is the development of practical fighting ability.
I strongly believe that this ability is intertwined with the other spiritual and mental benefits of martial arts. The development of fighting skill holds you to a more accurate and authentic practice of your chosen system. To reap the full benefit of a discipline, you must seek to understand it in its true form. Otherwise, you are merely dabbling in a parody. One must master fighting in order to master a combative martial art.
Economics and a “supportive” attitude may tempt an instructor to advance unqualified students simply because they have “paid their dues.” Over-ranking students does a disservice to the art. Incompetence spreads exponentially as unqualified practitioners go out to teach others. It fosters the cycle of dilution and consequent revision of countless systems.
New names are usually employed to uniquely distinguish each revision. This results in a thousand styles, or a thousand names really, all based on the same core techniques and hoping to accomplish the same goal.
Styles have different forms and formalities which make them appear unique on the training floor, but most times, once practitioners step up to fight, you cannot easily determine who is representing what style. The effective applications boil down to the same basic techniques.
Most martial schools share the same kernel of truth because they are all based on achieving effective fighting skill. Lots of excess baggage gets packed on in the process of revision and re-revision, with each new master presenting his own interpretation. There are plenty of genuine and useful insights thrown into the mix, but there is also a lot of junk.