Well, I can see that it may sometimes be entirely insufficient, but I'm having trouble thinking of why it would be actually harmful or any reason for not using it? Understanding the conflict better doesn't, as far as I can see, preclude further action.
Or do you just mean that sometimes it's beneficial to trick someone or not let them know what you want? Or that communication sometimes takes time that's better spent?
Well, there are always going to be times when a particular strategy works better then others. In terms of martial arts - I can think of any number of situations where communicate first wouldn't be the best option.