What is it with (mostly Asian) manufacturers arbitrarily deciding that most of us living south of the 49th parallel have no need for heated exterior mirrors on our cars?

Our 2001 Accord gets parked outside and yesterday morning it had a thick layer of frost all over it; heated mirrors would have been really nice. Our Mazda3 was like this when we bought it; fortunately the simple purchase and installation of Canadian wiring harnesses and mirrors connects the heat elements to the rear-window defogger circuit. Is it just as easy to retrofit heated mirrors to a 2001 Accord Sedan?