A command blunder results in a banzai? That's a great idea
Having not played the game, I'm not totally aware of all the factors involved in a frontal assault situation. I read about the reaction fire against advancing forces.
Billb said it best, it was a form of honorable death for the Japanese. I thought it could be a tactical last ditch maneuver, or lack of maneuver rather.
Making it a blunder makes the most sense. The commander thinks they are losing the fight -> let's have a BANZAI everybody