I agree with Gorath that in RL, spears were the most use in human warfare history, but i think too that once in close combat, even a Hoplite would use a short sword.
Still, spears are underpowered in warband compare to real life. But i guess it's a matter of balance, if spear+shield was as efficient as 1h+shield, it will be overpowered due to reach of the weapon (and nobody will use a 1h anymore...).