It always seemed obvious if you were making a hunting (stabbing) spear, you would run a lanyard from the knife (even it it's you 2nd or 5th) down the pole to you. Worst case, you can recover the blade, though I'd imagine there'll still be some struggle there. Otherwise, if one were to make a throwing spear, you would carve the point.

I always assumed that was the default case, and am always surprised when people make noise about "throwing away your blade". That obviously shouldn't happen.

J