Sound like Civilization and it's Discontents
.
But regarding Omnivores, I think most of them tend to be near the top of the food chain and not need to worry overly about predation. The two most obvious examples being Bears and Wolves, of course they'd still eat meat sooner then plants.
I think a lot of people have an overly romanticised view of nature (Disneyfied perhaps...). The Irony is that when we set up anything that anthropomorphises animals, we tend to make the prey animals the "heroes" and the predators into "bullies". The really big Irony is that we ourselves are predators (perhaps the most effective ones of all!), and our favourite pets are
also predators, namely Cats and Dogs. We're rather schizophrenic about the whole thing. I wonder how a vegan feels when he sees his cat brutally slowly kill and then
play with a small rodent. And then the cat quite joyously devours the whole thing...
I think the problem is that a lot of vegetarians live in cities and don't come into contact with animals frequently, so it's easier for them to anthropomorphise animals they rarely if ever see.
Not only that, but if we stopped eating/hunting a lot of these animals, their populations would grow out of control! We're part of the ecosystem too! Obviously we need to keep ourselves a little in check (nature did too good a job with us), but if we stopped killing animals altogether...