Fallacy
Eating meat is a personal choice just like being vegan is a personal choice, so everyone should just live and let live.
Response
From an ethical perspective, it is generally agreed that one individual's right to choice ends at the point where exercising that right does harm to another individual. Therefore, while it might be legal and customary to needlessly kill and eat animals, it is not ethical.
Simply because a thing is condoned by law or society does not make it ethical or moral. Looked at differently, it is logically inconsistent to claim that it is wrong to hurt animals like cats and dogs and also to claim that eating animals like pigs and chickens is a matter of choice, since we do not need to eat them in order to survive. So it is clear then, that eating meat is only a matter of choice in the most superficial sense because it is both ethically and morally wrong to do so.
Issue Responses
Humor