TN bans carry in government offices, and the Army bans carry on their bases and offices. Since we know that the signs do not stop determined assassins, we can only guess that the rule-makers are more worried about their own staff. And, more specifically, about their own staff going homicidally crazy without warning and just having a weapon on them at the time. That’s the only kind of problem that the rule against carry can even pretend to prevent.
So the rule-makers for the Army and the State of Tennessee assume that enough of their own employees (other than police) are unstable, murderous creatures with no self-control. And that they would, if unable to murder others immediately, cool down and not come back to work with a weapon the following day. Either that, or they assume that the treatment they get at work would make anyone snap.
And these are the people presume to tell the rest of us how to live?