I believe the motive is quite clear. The General is simply unwilling to speak the truth in this environment.
Remember that the 1930s Army had to speak carefully of the Japanese even as the Imperial Army was raping China,and that Patton dropped vocal(and correct) support for American tanks and armour because his superiors preferred the traditional horse calvary.Patton was then still in uniform when the U.S. needed a leader after the initial disaster in North Africa.