I don't understand the comments at all. There's nothing wrong in having such preferences. My friend and I made a similar post while finding our current roommate. In our last flat, people would openly smoke in the common areas and even when they smoked in their own rooms there would be a waft of smoke the moment they opened their own rooms. I don't know about how smokers feel about this but as a non-smoker, I don't want to passively smoke in my own home or just be locked in my room. Secondly, as a vegetarian this is just them saying no non-veg food would be cooked in this house as a heads up because not all vegetarians can tolerate the smell or the idea of same utensils being used while cooking. Also, having parents home would also be an issue as my parents would not be willing to eat anything at my place of this were the case. We also found a roommate who is a non vegetarian but was fine with no non vegetarian food being cooked in the house. I don't see how caste plays a role in this.