Another thing to consider is that it might be dangerous to carry a sharpened spear with you. If the ground you're traversing is diffucult the risk of injuring yourself on a sharpened stick might be too great.
IIRC Meriwether Lewis carried a picaroon as a walking stick on his cross country trip. Once he had just shot something for dinner when he was charged by a grizzly. Empty rifle! Oops! Lewis lit out for a stream and waded in. Then he presented old Ep with a spear point to his nose, as the bear entered the water. His journal recorded that “The gentleman refused the combat.”
