This is exactly the stupidity of the general public that causes the issue of the OP
They are not "making up their own rules" they have read & remembered the section prohibiting weapons, probably because it has been specifically shown to them.
Then because you and other idiots like you lie &/or hide posting an item that is allowed under another different section (guns for sporting use) they are not corrected and therefore educated that in fact the item is perfectly legal to declare & send.
Do not dare to complain about a situation that you deliberately fail to address when given the opportunity.