Have you eaten in many low-quality restaurants lately? And complained about the food to the server?
The last time I had a problem with my food (the vegetarian pasta that my partner ordered... who has been vegetarian for decades because of strong personal beliefs against harming animals... had chicken in it which she ended up eating and feeling terrible about)...
I brought that to the attention of our server, who just said "oh sorry, I'll bring out another one".
There's one example of a server who didn't get a tip.
Another time we were eating pizza with olives on it and the olive had a pit in it that almost broke my tooth... am I supposed to ask that the server please inspect every olive on my pizza and make me a new one?
Or ask the server to take back my stir fry that has almost as many ants in it as there is rice, and ask them for another one?
No, I wouldn't think so...
A restaurant is a team (who typically share tips amongst everybody in the restaurant in my experience), and if the team screws up, the team doesn't get tipped.
When I worked at a restaurant and served food, it was on me to make sure that everything that was served to the customers was perfect. If it wasn't, I would send it back to the kitchen.
I don't care what people think of me and my levels of compassion for restaurant staff.
If I am not enjoying my time in your restaurant, I am not going to submit to the gauntlet and tip on the way out the door.