^^ Totally agree with the last line above.
I do have a self-imposed dietary restriction.. I'm a vegetarian. So you know how I deal with it? I order things that don't contain meat. Simple.
I am actually allergic to scallops and some other shellfish but since I stopped eating meat it isn't much of a thing, but when I did eat meat, I never went to seafood restaurants because of the risk. I learned this the hard way as a teenager in Key West - went with friends and ate something without seafood in it but still ended up puffed up like a balloon. I don't expect a restaurant that serves hundreds of people per day to make special accommodations for me. Most kitchens aren't full of skilled chefs, they are line cooks that know how to make what is on the menu and have certain ingredients available. They are cooking quickly and for a lot of people at one. The way I see it, the menu tells you what they have and you order from that. I would never look at a chicken sandwich on a menu and ask if they could make it with a tempeh patty... so many places wouldn't even have that.