The firearm was invented as a weapon of war by the Chinese to give the Emperor an advantage over his enemies. It was never intended for civilian use. When Marco Polo went back to Italy, he brought some back with him to give the Venetians the upper hand against pirates and the other Italian city states aligned against the Black Nobility. Then the papacy got involved with their manufacturing, which then, eventually, allowed for civilians to use them. But the original firearm was never intended for civilian use. Which is the main reason why the D's say we don't need them.