As a vegetarian, I can really empathize with the points made earlier about why vegans/vegetarians come across as pushy sometimes. But I will never, ever comment on someone's choice to eat meat.
What I have come to realize is that there are so many horrible things going on in the world, one person really can't research, learn about, and try to fix them all. You have to look at the issues you care most about, and do your part to solve those problems.
I really think that most people are trying to do what they can to help. Some people choose to be vegetarians, some volunteer for soup-kitchens, some donate to Saint Jude's, some adopt and love at-risk children, some go into the Peace Corps, some knit prayer-blankets with their church groups... but most people are trying to do something.
I have chosen to be a vegetarian, bike or use public transportation to commute to work, and have volunteered to coach local Special Olympics swim teams for several seasons. Those are some of the things I care about.
My in-laws, on the other hand, eat plenty of meat, but they took early retirement from their full-salaried jobs to work as full-time volunteers for Habitat for Humanity International. They spent years living out of suitcases while setting up affiliates all over Asia. They led the first Habitat teams in Sri-Lanka to begin rebuilding after the tsunami. My best friend, also not a vegetarian, volunteers her time providing free literacy training to adults.
If my friend, husband, in-laws, co-workers, etc. were to become interested in vegetarianism, I would be elated and share with them whatever I could to help. But if I try to coerce them into it, or become judgemental of their eating choices, I am taking their time and energy from the things they are addressing that I, frankly, am not really doing much about myself.
So I am grateful for the things they do to make the world better; I am happy to spend meals with them, happy to bring myself to their tables or invite them to mine... as I will certainly be doing tomorrow (Happy Thanksgiving, all!)