If a person is equated with animals, then yes, there are no problems, you can eat anything and anywhere, because a person is an animal at the top of the food chain. However, there are "strange" people who refuse to consider themselves animals. They believe that a person, unlike an animal, has free will, conscience, we experience compassion, pity, love, etc. This indicates that we can not live the life of an animal (which realizes only its physical needs), but also in the sphere of emotions and soul. Therefore, they believe that there is no need to kill animals for food.
Well, for some people, meat is not a product, but the corpse of an innocently killed animal. In other words, there are certain categories of people who also bring animals into the zone of individual altruism (for most people, this zone accommodates a couple of relatives and friends) A comparison with predators is incorrect, because predators, also eat feces. That is, not everything that is good for a lion is good for a person. Well, by yourself, you need to understand that under the words ETHICS and ETHICAL - you can mean anything. That is, all sorts of vegans, etc., first of all, crave attention.