I agree. A local restaurant chain here that is a family-style, middle price range outfit is always happy to change their regular menu for my family. My husband loves their house salad but is allergic to celery - they cheerfully leave it off. My son hates shrimp (he may be a changeling! < g > ) but loves one of their shrimp dishes, so they fix it for him with chicken instead. No change in price.
I regularly change things out on the menu such as fries for mashed potatoes or brocolli for spinach and its a not big thing. When you do that for customers they come back again.