Someone smarter than me said it:
Two mountain bikers are powering up a steep, technical hill. The one with flat pedals steps too shallow, flipping the pedal into his shin and crashing. He’s lying on the ground, rolling in pain.
The clipless rider powers right past him, securely attached to his pedals. He gets to the steepest section, stalls, tips over, and rolls down the hill. He’s lying on the ground, rolling in pain.