Many states have enacted concealed carry licenses in recent years with no adverse effects. I don't think Missouri residents have anything to fear from this legislation (unless you are a mugger, stalker, or rapist).
As others have said, criminals don't sign up for concealed carry permits, and fears of gun control advocates that people that carry guns will immediately whip it out and start blasting any time some one cuts them off in traffic have not materialized.
And I would be a whole lot more scared having a gun drawn on me than a sword personally