I find while mountaineering when i have depleted all my reserves, and am running on nothing my mind rehashes things that make me angry to keep moving. This is the "motivation" that fuels my fire when nothing is left. I don't conciously do it, but this is my bodies natural response.
However when rock climbing for me the essence is to be loose, and very free. When angry you trap your mind, and can't break frames. This for me is the sole fo rock-climbing. I don't climb when angry cause i just worsen the situation, and am wasting my time.