"Inspiration" to fight?

I don't think it's right that the troops would shoot at their own soldiers that ran back.  Why even keep fighting if you're just going to shoot your own men?  I understand that the generals did not want their troops retreating, but shooting your own men is just plain dumb.  Where would that get you?  There is no benefit of doing this besides scaring your own troops.  This is not inspiration, this is a threat.