The difference is the mind set. Those schools are taught to use everything and anything as a weapon. To attack vital areas. To fight dirty. If someone trains for years in a system like this, then guess what? In a self defense situation, he will be looking for those vital areas. He will be conditioned to fight dirty, and to use whatever as a weapon. Of course boxing, and MT and sport systems are useful. They are more than useful. But to say deadly systems are worthless, or to pass them off as school yard bullshit is silly. To say that deadly techniques don't work, is also silly. Those techniques are backed by the nature of the human body.
Have you actually been in the military or are you just talking out your ass? When I was in we barely got any hand 2 hand, you had to train that shit on your own time just like every other civvy. I'd put my money on Roy Jones jr over any spec op.