And you miss the point of language.
I really think the whole point of the initial bullet/gun comment was that once it has left the gun, it is out of your hands. It is not about how guns work. It's about not being able to take back your actions. The advice to treat your words on a public forum as if it were the same as firing a gun, would be entirely accurate. What has been fired/spoken and then impacted/read/interpreted, does not simply disappear because you say it does. Arguing ballistics is like arguing whether you used a particular word or punctuation. How you punctuated or in which direction you aimed the gun, has nothing to do with the definite and lasting consequences of a bullet hitting a target, or words hitting their audience.
It isn't an argument about how SERIOUS words are, but that they can't be taken back once they're put here. Some words are like nerf guns, completely irrelevent and just there to fill space. Some are world altering. The point is you can't take them back once they've hit their target.
You mention people taking things too seriously, or saying people are being extremely over dramatic for saying words are like a gun. Nobody else thought they were being unreasonable or outlandish.. you are apparently the one getting far too upset about a simple simile. If I say a Giraffe is so tall it's like it just goes on forever into the sky, are you going to call me crazy for making a comment regarding the enormous height of a giraffe? Of course this is a silly comment to make, but not as silly as it would be to get mad about it.