[QUOTE=Lizard]
Because either way, you could wind up dead, that’s why.
[/quote]
The reason is different, and reasons are relevant. Animals can’t think things through. If they feel their lives are threatened, some animals will attack out of sheer instinct. Humans, like the Crips and Bloods in your example, can act out of greed and malice. The courts take such motives into account when they prosecute and sentence people for crimes. If a person who killed acted for the same reasons an animal does, out of an instinct for self-defense, he would not be judged as harshly as a person who killed for malicious or self-aggrandizing reasons (or would perhaps not even punished at all) . Yet you would, if I understand your argument correctly, have the animal killed. That does not make any sense even based on your own reasoning.
Animals don’t kill out of self-interest in matters of self-defense. That’s anthropomorphism. They act out of instinct.
You’re not protecting anyone by killing an animal who, in the normal course of events would not go near a person, kills a person in self-defense. You are committing an act of either retaliation or overreaction. Killing the sting ray referred to in the OP would likely not have saved any future human life, and would be an absurd response IMO. The sting ray randomly jumped out of the water and hit a woman, killing her. Accidents happen, people and animals have run-ins. “The animal should automatically die to proect humans” stance doesn’t seem like a rational, sane, or useful response in a situation like this. If I am misinterpreting you, please correct me.
Usually, though, it’s not about defending humans against vicious killer animals. No one has suggested that an animal should be allowed to run loose who wantonly attacks people. If the animal can be rationally judged to be an ongoing risk to people, then I can see why it should be killed. Most times, though, that is not the case.
Example: my friend lives on the Jersey shore. A nurse shark was by a sand bar, minding its own business. If it had been left alone, it would not have approached people or harmed them. The man decided it would be a good idea to chase the shark into the shallows, then pick it up by its tail. It whipped around and bit him. Should the shark be killed? IMO, no, but the man deserved that bite for being a moron. THAT is called “evolution.”