The fixed bayonet is one hell of a morale buster. If you see 200 men charging at you with fixed bayonets you think twice before you open fire.

In WW2 it was often used by the Brits would they need to get out of situation they would rather not be in. Wolfheze is a good example, where Brigadier Hackett himself led multiple bayonet charges, losing men, but reaching the objective.

If you attack a hill you will lose men anyway, it's a given (atleast against enemies that are as good as you). So you have to use unorthodox tactics.