This is because “stand your ground” simply means that, if you reasonably believe that you face imminent death, serious bodily injury, rape, kidnapping, or (in most states) robbery, you can use deadly force against the assailant, even if you have a perfectly safe avenue of retreat. In non-stand-your-ground states, when you face such threats outside your home (and, in some states, your business), you can only use deadly force against the assailant if you lack a perfectly safe avenue of retreat. In no states are you allowed to shoot someone who is simply shouting at you or moving towards you loudly and aggressively, unless you reasonably believe that you’re in danger of death, serious bodily injury, or the other harms I listed. (When the person is coming into your home, in many states you can indeed shoot, but that doesn’t apply to confrontations on the public street.)
Pro-gun-control folk should read the entire article. Hell, so should pro-liberty folk. Via What ‘stand your ground’ laws actually mean - The Washington Post.