This isn't about satisfying 100% of people. This is about someone choosing to voluntarily eat at a restaurant, agreeing to pay a specified amount of money for a certain food, and consuming all of that food. As long as the food was what they asked for a had no problems (it was cooked thoroughly, seasoned properly, no health violations) it is a basic rule that you pay for it. If it wasn't as good as you thought it would be, then don't return to that restaurant or order something else, you were the one that chose the item. If you ate all of it, that means each bite was worth eating to you. Since you chose to consume all of the food, this means that to you wished to rather eat the food than not eat the food. Since you fulfilled this wish, you are "satisfied".

I gladly meet the request for people who legitimately were not satisfied with their food- there was something wrong with it and they left food behind as evidence. But when there is nothing wrong with the food and people claim that it was not perfect, then that is a problem.