The other analogy I like: It's like hating stop signs as evil,* because most of the time, when people drive past them, they end up getting into driver's side collisions with another car -- so it must be that the signs want to kill drivers. And, to boot, they're the color of blood... Meanwhile, the signs can't read themselves, and probably have no idea they're telling people to stop.

*I originally came up with it to counter the American superstition that black cats are unlucky while in countries with a British commonwealth heritage black cats are lucky (::smiles at your icon::). Both versions of this superstition come from when the Greeks started trading with the Egyptians. Hecate was the Greek Goddess of magic and crossroads, and in Greece, her totem animal was a black rabbit. When the Greeks encountered a country where cats were sacred, Hecate "Adopted" them, too. So if a black cat (or rabbit) shows up walking down the road in the same direction you are, it's confirmation from the goddess that you're headed for something good, but if a black cat crosses your path, it's a sign that there's bad luck ahead. Brits latched on to the first part of that, and Americans latched onto the second.