I certainly would not hate someone for choosing a way of life that prevents the slaughter of animals. Your heart is there and you are doing it for the right reasons.
The main issue is that the majority of people on this earth are omnivores. We've been that way since the stone ages. You just have to look at cave paintings of our ancestors hunting mammoths, or go back more recently to native american tribes that hunted deer, caribou, buffalo. But some vocal minority of vegetarians and vegans want to impose their values on others (the ones who will be giving me thumbs down I bet...). And much like me telling you to eat this hamburger and wear the leather shoes I bought for you, it would not be right to ask that.
Now you pointed out a person who offered a sandwich and when you said you were vegan, they simply said "fair enough" and indicated in no uncertain terms that he respects your lifestyle as long as you don't try to impose on his eating habits. I don't see the anger or hate there. It's much like a non-smoker saying I respect your right (to smoke), just don't do it in my house or expect me to breathe it in.
So good for you for choosing a life that protects animals. And I promise I won't be eating any human babies any time soon. But I can't guarantee the same about veal. Sorry? ;-)