Most martial arts organisations will have theoretical components to their syllabus. Usually, this is to provide an insight into the language and culture of the country from which the art originates. I find the academic side very easy to cope with, as somebody who naturally learns in the academic style. Many artists though, find the academic aspects tedious and difficult, and so tend to reject their usefulness.
This begs the question: is the theoretical side to martial arts necessary? I would argue yes.
Firstly, martial arts contain dangerous knowledge. You don’t want to wrong sort of person to be taught martial arts, and by the wrong sort of person, I mean of course somebody who would use that knowledge in an offensive manner. And there are plenty of these people who train already, I see them often. A strong academic presence makes it harder for these people to progress, and hence acts as a barrier for them to learn the more dangerous techniques. Aggressive people would find it hard to maintain the patience required for academic learning.
Secondly, one could argue that it is disrespectful to train in the martial art of another culture, but reject all other elements of that culture. It seems almost greedy to take only certain bits of that culture. The academia commands a certain respect towards the culture. As is well known in martial arts, respect is always an important virtue.
Thirdly, it adds another layer to any examination procedure. For example, there may be two students, both equally keen on the martial art they are studying, but one may naturally be better at the movements, as some people are. In a grading this looks as though one is more enthusiastic than the other. Everybody has strengths and weaknesses in different fields, so those who struggle with the physical tasks may excel in other areas, such as language or history. Studying academic aspects provides an opportunity for some to demonstrate their interest despite a drawback.
Fourthly, it is a way of standardising education. Some organisations become very heavily fractured, giving rise to a multitude of descriptions of the practical elements (which is particularly bad in English, which has so many words). Using another language, one that is unfamiliar to many, makes it harder for such uncertainties to come about when there is communication between these different groups.
The most common point made against academic studies is that they waste time that could otherwise be used to improve your technique. This is definitely true if one is intending to enter a competition, but as for a general progression through martial arts, a grandmaster would need a very broad knowledge of his or her art. That knowledge is easiest learnt along the way.