To answer the topic question, yes, civiliity can exist with stupidity. They are not mutually exclusive categories. I find it amusing that you are overly concerned with the gun-weapon politically correct distinction but fail to recognize that your contrasted categories of civility and stupidity are not mutually exclusive.
So Topgun, calling a gun a weapon is what you would consider as stupidity? Is that right?
I also find it amusing that you think that calling a gun a weapon is stupid. Given that stupidity refers to being unintelligent or slow of mind, that says a lot about what you are saying about the people who use the term. The amusing part is that you have assumed them to be stupid without consideration for being ignorant. A person can be extremely intelligent, but ignorant of a given topic. You might catch more flies using honey instead of vinegar. More than likely, folks calling guns weapons are not stupid as you imply, but ignorant to your reasoning and justification or to the distinctions of refering to the gun or weapon as would be appropriate given the context of speech.
Are these failings of term useage by you stupidity? No, but they do show ignorance. Ignorance is not the same as stupidity, but some stupid people are also ignorant as well.
As near as I can tell, you are just engaging in one of those silly politically correct conformations. You are not engaged in strategy nearly as much as you think, but nomenclature.
In getting to the idea of context of use, only rarely do I shoot just a "gun." I shoot a weapon as what I am doing is self defense training/practice. In that context, it is being used as a weapon and that is what it is.
Go shoot your guns all you want. I will train with my weapons.