+1If it can be utilized as a defensive measure to avoid deadly force, and used responsibly, then I see no problem with it.
If you are just going out pointing a gun at anyone that get's in your face, then well ... that's not responsible. If a vocal defense fails, and you have little realistic choice, why wait for the situation to become a deadly force incident.
If you can defuse the situation by pulling a firearm, then it's a win:win situation. You are not harmed, the offender is not harmed. The situation was avoided. Do you run a risk of indictment? Sure.
I see the whole "wait until it becomes deadly" situation similar to waiting for the person to throw the first punch. It's a risk.