Because criminals do not register their guns. Instead, decent hunters, gun sports club members and antique collectors are hounded down. No wonder, as Heston pointed out, the criminals are laughing at us. He stressed we are all North Americans and the border between us is really just an artificial and imaginary line drawn by politicians. Geese cross the border at will.
Deer move back and forth.
Salmon rush inland from the same ocean. They are no respecters of politics. They pay presidents no heed, nor prime ministers. Heston repeatedly noted every time the politicians manage to rip away a freedom or right from us, they become even more encouraged to take another step. Soon we really will be serfs of the state.