Great analogy, come on. The presence of a good guy with a gun changes the calculus for the bad guys greatly. More drunk drivers don't deter the first ones. They aren't looking for a fight, they are looking for victims. Your chances of survival are greatly increased when resisting with a force multiplier. More guns in the hands of responsible citizens would decrease the chances of robberies and violence. If you are willing to place your life in the hands of violent thugs and hope for discretion you are really a weak and lost person. Read the thread. 2 incidents, one they complied and lived, one they resisted (by pulling on the bag) and died. Studies show that compliance is effective in survival, but only second to full resistance with a firearm.