Good for you. Why do you assume I'm being a dick?
Quite frankly, because that's the chain of events I've always observed. You may be an exception, and if so, I apologize.
It normally goes something like this (Cast: Waitress (W), Meat Eater (ME), Vegan/Vegetarian (V)):
ME: I'll have a steak. Rare please.
V: I'll have the veggie burger. Do you know if the fries is fried in vegetable fat.
W: I don't know.... I could ask in the kitchen...
V: Nah, never mind. Just give me some salad with it.
W: OK.
ME: Are you a vegetarian?
V: Yeah.
ME: Why?
V: I oppose the meat industry. It's actually quite gross. The animals are practically tortured...
ME: OK. I love my rare steak.
V: I see.
ME: You know... aren't you a bit hypocritical?
V: Yeah, perhaps. Still, I like to be responsible for as few unnecessary deaths as possible.
ME: You can hardly go outside without killing an insect you know.
V: Perhaps, but at least I make an effort. And I think there's a difference between cows and insects. Say, did you see that movie...
ME: And if you're killing insects anyway, you might as well eat meat.
V: That really doesn't follow...
ME: Hypocrite!
<at this point veggie dude turns very defensive, and it ends with the meat eater assuming all vegetarians are assholes>
Your experience may be different. But it's what I always observe. Over. And. Over. Again.
And yes. I eat meat. I never question them, and I never get questioned in return.