You seem to be implying that "hunters" are people that go around killing anything and everything they get a chance to.... and if that's your position, I suppose they're probably shooting up some farmer's livestock too.
You also seem to be trying to set the rules for what is acceptable and what isn't. Lets see, killing for food is okay, but for any other purpose is bad. So... in order to fit with your standards, if I go duckhunting, I don't dare enjoy myself.... otherwise I'm doing it for the sport. If it was just for the meat, I'd be down buying meat at the grocery store like you.