[(speed, fpx x speed) x (weight in grains)] divided by 450,240 (gravity) gives you about 310 pounds of energy for a 2 pound spear at 100 fps. Between a .38 special and a .45 auto and 4 or 5 times most bowhunting combinations. Obviously there are other factors, but I'd have to think a spear penetrates and does significant damage. I doubt there's any scientific reason for a ban at all, simply emotional objections.
I think your right.