I can tell you from my own research on this matter that Hand-to-hand combat is largely a myth. Does it take place? Yes, but so rarely that it is of no training or doctrinal importance.
Training people to stab sand bags with bayonets contributes nothing in comparison, because you can't suffer harm, and thus I can see no use for it
Chest Puller is rolling over in his grave reading your posts Mr. Owen..

The techniques they ingrain in you do serve a purpose of ingraining the overall Warrior spirit, that refusal to give up the fight.

The Marine Corps' Martial Arts Program has also helped a great deal of Marines with PTSD issues as well.

Plus, the Marine Corps has Pugil Sticks that every Marine has the opportunity to enjoy. That is definitely putting this hand to hand/bayonet training in context with a more stressful environment.

When you find yourself in a situation that requires a last line of defense, I'm sure you'd be greatful for the training, not to mention the mental toughness and mental agility that the training itself inspires.