Scylla, just to be clear, I’m not a vegan. I’m a vegetarian, so I’ll amend your question.
(As an aside, you’re going to get a lot better dialogue by asking, “Why are you an X?” then you are by saying “X’s are wrong, and here’s why.” At least from me, anyway. I’ll give like I get. Tough but fair, as the game theorists say.)
(Further aside–ain’t nobody saving the world. We’re all gonna die in the end, every last one. What matters to me is what I do while I’m alive.)
(Another one: Any bullets shot at Milo will only graze you to the extent that you choose to associate yourself with such transparently idiotic statements. I’m sure Milo will have all sorts of explanations for how his observations are completely correct. Anyone who buys that, I’ve got a bridge I need to unload.)
(Final aside: Yes, some veg’ans give really uninformed, stupid answers to the question. I’m as embarrassed by them as I am by what Lib refers to as “hand-stabbing atheists.”)
Anyway, you asked why I’m a vegetarian. Part of the answer deals with the scope of my vegetarianism. I don’t eat any animal flesh – no beef, no veal, no pork, no poultry, no fish. I do eat dairy. I’ll eat eggs from free-range chickens only, and I pay extra for them. I will not eat cheese cultured with rennet if I can avoid it. I do not wear leather at all.
Why? Well, because I decided that, based upon the widespread horrific practices in the factory-farming industry, which produces the lion’s share of the meat consumed in this country, I would do everything in my power not to contribute unnecessarily to the suffering of sentient beings. Sentient in my judgement, anyway. I subscribe, at least in part, to Peter Singer’s maxim that the difference between humans and nonhuman animals is not a significant enough difference to justify causing them unnecessary suffering. And factory farming, in my opinion, is unnecessary suffering.
That’s it. It’s that simple. If I was so inclined as to kill an animal myself, swiftly and humanely, I’d eat it. But I don’t need to–I get along just fine without it. I believe that molluscs and shellfish differ quite significantly from mammals, foul and other marine animals, but I don’t like to eat them anyway.
I’m certainly not stupid enough to think that complicated issues like research allocation can be subjected to reductionist answers like “stop eating meat,” although it is fairly evident that the resources involved in raising, feeding, transporting and slaughtering animals somewhat exceeds those used for produce. Also, that a given acre can yield more nutrients for human consumption from plant matter than it can from animals.
Anyway, that’s my answer. Ask another vegetarian, and you’ll get different answers with different restrictions, some smarter, some dumber.
As far as the faith-based thing, I don’t think it matters; other people’s dietary habits are still none of your business. Now, if they’re advocating as a matter of public policy vegetarian-friendly practices that you think will be harmful to everyone for some reason, speak right up. If they’re rude to you, tell them off. But it all comes down to what each of us believes, what our ethics are, and how we practice them, and as long as nobody is causing you harm, it’s presumptuous to question them. Otherwise, you’re just attempting to exercise control over their lives. If they believe that it’s bad to eat little animals, it’s not inherently any sillier than any other belief.