It's not that they don't apply to us, it's that they don't apply to many vegetarian cultures. I remember a lesson in history class about how, when Buddhism arrived in Japan and preached against meat consumption, fish were so ingrained in Japanese diet they had a literal revolution to keep fish on the menu. Not just the stereotypical things like sushi, but I guess they like fish so much they'll eat dolphins (which their cuisine has always considered "fish"), which to me is equal in gravity to cannibalism, this coming from someone who doesn't necessarily like them. Because if an animal is mindful enough to engage in diplomacy, why the hell are we eating them?

Sometimes this "except you" attitude is also applied to insects, though that seems to be less culturally specific. If people need to for some reason reconcile vegetarianism with needing meat, I don't understand why they don't do the obvious thing and just separate meat of animals killed in cold blood from other meats.