You make an excellent point! At the moment, dishes you serve are scored based on a set of rules according to the customer's order, but it's overall pretty lenient and you'll often get tips even without a perfect meal, which I guess is especially odd when you just serve them raw ingredients. I'll probably add an additional rule for "Is Soup" or something along those lines.
Thanks for playing though! Glad you enjoyed and thank you for the feedback! :)