I don't have a dating profile (I've been in a happy relationship for almost 4 years, and converted from an omni after meeting my healthy vegetarian boyfriend).
I am, however, finding the need to "apologize" in my responses to ads for apartments. We're looking to room with people to save money, and holy cripes, it's proving difficult. We've got 3 snags: we're a couple, we've got a cat, and we're veg*ns. Being veg*n has proved more of an obstacle (in terms of denials) than being a couple and having a cat, combined. Some people explicitly state, "NO VEGETARIANS, we love our steak in this kitchen!" or something to that effect.
So when I answer ads that, at best, don't mention diet, I do say that we're veg*ns because I don't want to seem like I'm hiding it. But then I follow it up with,"We don't mind if you eat meat." I figure we could always get a mini-fridge if food storage becomes an issue (I'm a Fridge Freak, and everything has its own place -- no arguments!), and we have our own pots and pans and dishes/utensils.
It's tough, because I actually do care. I'd feel sick to my stomach if I woke up to the smell of bacon frying in the morning, and if my roommate(s) insisted of eating carcass at every meal, I'd find an excuse to eat in my bedroom with the door shut. But what's a gal with a light wallet to do? It's a tough situation, and so is being lonely.
People will make apologies and compromises because getting to a better place is more important at the moment.