Seems like advertising that there are guns in the house for thieves to steal when no one is home. Unless all of the guns are in a giant safe. And even then, criminals don't care. They will bring in a dolly and steal the whole safe.
I've heard of criminals who come in and steal people's refrigerators.
Seems like a mat that someone who didn't have any guns would put out just to try to scare off would be criminals. Like a sign that says that you have a house alarm system when you really don't.