Here's the thing, though. At a restaurant, I don't worry about offending the chef if there's something I don't care for. As I said before, my SIL gets offended if every bit of food is not gone from the plate and will grill you as to what was wrong with it.
One of her adult sons asked for salt once and she went on and on about how she'd perfectly seasoned the meal for about 15 minutes.
In her case, this is just one of the ways she tries to control everyone and I really don't like other people trying to control my food intake. She's the only person I know who plates the food for guests.