Ian, believe it or not I am going to take issue with some of your statements here. Firstly, I don't think that "interested" was asking for any high moral ground with that statement; rather, he makes a valid complaint: the airlines, who offer vegetarian and kosher meals upon request, do a very poor job with those meals [of course, they don't do a particularly good job with other meals, either, but they do usually put more effort into them].
Here again, I will take issue. It's not an either/or situation at a restaurant, Ian. Why shouldn't a restaurant be able to serve a meal that doesn't contain meat? Most restaurants I visit do have a few vegetarian dishes on the menu. After all, you not only cater to vegetarians (including those Buddhists, Hindus and Jainists who practice religious vegetarianism) but also orthodox Jews who can eat pareve and dairy meals, so you appeal to a fairly extensive group of people. And I would expect most restaurants to be able to serve a meal that didn't contain e.g. peanuts and peanut products to a patron who had a severe allergy to them.
However, I do agree with you that someone running a B&B is under no obligation to cater to vegetarians, and I would expect any reasonable veggie to ask ahead of time to find an establishment that would cater to their needs rather than assuming that they'll be accomodated without prior agreement. Also, I would not take issue with your position re vegans, as I see their needs as placing an undue burden on chefs, such that they should seek restaurants that explictly serve vegan food.
On this we are in entire agreement.
Mark Lipton