"Spirit of Harmony", Basis of Japanese Mentality, lectured by Toshiyuki Namai
It is said that the people in Japan are not good at aggressive discussion on business. Historically speaking, there has been a belief that "spirit of harmony is very important in the society." Japan is such a small country consisting of four major islands and many people dwell in such a limited geographical condition. This is one of the major reasons why "harmony" is quite important in the nation.
Also, another element (reason) can be found. In Japan, the Seventeen Article Constitution was established by Prince Shotoku on April 3, 604, that is the "oldest" constitution in the world. Article 1 of the Constitution provides that "The harmony is the most important thing."
Of course, this is not like a "civilized" or "modernized" constitution. There is no separation of powers and rigid frame of government under this "primitive" constitution.
Apart from such a legal standpoint in consideration of jurisprudence, I can tell that it is really valuable to recognize that this "spirit of harmony" is a basis of mentality of the Japanese people. Then, the reason of question is so clear, "why the Japanese are not skillful in logical discussion."
Consciously or unconsciously, the Japanese avoid doing "aggressive discussion" and attempt to make "harmonious communication" all the time. This is conspicuously recognized as a "Japanese strategy" to conduct the business smoothly.