You lost at equating the slaughter of food animals to the torture of sentient, thinking people, who are pretty much just like yourself, with hopes and aspirations and families of their own. I think part of it is the empathic realization that you might have just as easily been in that person's place.
I've hunted, and had my hands in the blood and guts of my prey, which I later delighted in consuming. I've also witnessed people die terribly bloody and painful deaths. Animals may have a general sense of panic when you look them in the eyes as they die, but for me at least, it's not at all on the same level as when its a person looking back at you. Not even close.
I have an uncle who is going on 70 who will not eat pork, not because he's Jewish, but because his family on the farm made him watch the slaughter of 'his' pig when he was a child. He viewed that pig very much as people view their dogs and cats. Of course it's anecdotal evidence, but I'd say he was scarred by the experience.