"Cows were put on this earth for us to use them. You don't eat cheese? That's stupid."

I am ever amazed by people's responses to "I'm vegan." I'm at an event where they ordered pizzas and was told, "We ordered one with veggies for you." <Sigh> So I said, "Thank you; that was thoughtful. However, I'm vegan and don't eat cheese." I was looked at over glasses and after a long sigh told this gem:

"Cows are here for us to use their milk. You should start eating cheese; that's stupid"

Really? Really? People exclude dairy from their diets for MANY reasons and I just don't understand how judgemental some people are. It's getting to the point where I feel like people view veganism as a religion and because it's different from what they practice, they view it as unacceptable/inconsequential/immature/just plain stupid.

I'm not a hardcore vegan. I occaionally partake in baked goods with butter or cream; if I'm out somewhere with really superb sushi I might have a few rolls. Cheese I avoid at all costs, however. It makes me feel bloated and sick after I eat it. So no, I'm not going to eat the veggie pizza and yes, I'll just endure the never-ending criticism. But I won't like it and it probably won't cease to amaze me.