That question has nothing to do with Caste specifically. It is more of a thing between North and South Indians where North Indians are usually more of a meat eater than South but again it depends on the region. Plenty of North Indians are hardcore Vegetarian. It has nothing to do with caste or religious affiliation. Being a vegetarian in general is looked down upon even in America, isn't it ? Go watch the movie "escape plan" where schwarzenegger says "You hit like a vegetarian". Also the vegetarian question comes up with Indians because it is difficult to go to a non Indian Restaurant with hardcore vegetarians as they may not find many options. So when a group of Indian coworkers go out to eat, they have to know who are hardcore vegetarians and choose a restaurant accordingly.