That's why you carry a fighting knife and a bayonet. The fighting knife is supposed to be sharp - it's a knife that cuts, stabs and slices.
The bayonet however is not supposed to be sharpened. The bayonet is a ram-stabbing (hence, bayonet) and slashing weapon that uses the weight and force of the soldier behind the rifle to inflict the damage. The point is blunted, as it is supposed to HURT when it gets slammed home - and notice I didn't say 'just a little'....I said slammed home so that even if the opponent doesn't feel the bayonet he is equally hurt, surprised and debilitated by a rifle barrel punch to the guts. If you want to know how much force it takes to slam a bayonet home, try it on something equivalent to a human body and you will see for yourself.
The edges of the bayonet should not be sharpened to excess, that is, to a fine edge. The slashing force of the bayonet is delivered with the weight and force of the rifle and the bayo is just the extention to the barrel. When you slash across an arm, leg or throat, it is the force of the 'slash' that causes the cutting wound and the resultant tissue, muscle and bone damage, not the sharpness of the blade.
JMTCW. Mikey.