The vast majority of people who don't eat meat honestly don't care about anyone else's dietary choices. The reason it comes up is because most people assume everyone eats meat. If I was never offered meat, I'd never have to tell anyone that I'm not going to eat it.

There are always going to be outliers like that girl, but compare the relative frequency of seeing people like that vs the absurd number of bacon products (jelly, soap, toothpaste).