I have many friends and acquaintances who are vegetarians, especially at work. At a hospital, whole departments can tend that way. I don't often talk with any of them about their reasons. I imagine they vary among the various elements of health, identification with creatures with faces, and disgust at eating things with blood, fat, and muscle. None of those moves me greatly, but those make sense to me.
Twice this week I have gotten into chats with vegetarians who were quite emphatic when discussing human beings in another context - overcrowding in her once-small childhood village for one, general coarseness and deterioration of culture for the other - how much they disliked people in general and considered animals more valuable. They didn't tie it in to their vegetarianism, and I didn't think it was nice to do so myself. It was the first time I'd made this association.
The dual experience prompted me to think back over other conversations in my lifetime. Obvious selection bias here. I remembered other vegetarians who had large swaths of humanity they pretty openly disliked. This just creeps me out.
BTW, the sound of gunfire in the distance at present. Either hunters, or hunters practicing. Couldn't do it myself, because I'd hate to succeed. Wouldn't like to butcher an animal.