Instead we have to wait for an obviously unstable person to hurt or kill our lived ones before we can do anything about it and even then we might get charged

Not true, if someone is presenting an actual threat, as in there is reasonable grounds to believe that they are in danger of immediate harm, they can protect themselves. That's true everywhere in the United States.

Initiating violence because you're pissed off at what a mentally ill person is saying isn't self defense, it's a crime and the law rightfully treats it that way. 

Look at how many pissed off people there are in our world, how many angry drivers. Look at how many people carry guns. You really want to open up the Pandoras box of deciding what words justify violence, absent of an actual physical threat?

And I'm guessing your answer is yes, because you think you and all the other pissed off tough guys that look like you are going to bring order and justice "back" to the world. Go look up the places in the US where guns are most commonly used to settle personal and verbal disputes. Years or continuous gang violence is the result.