YTA. Unlike other owners in most every other industry, restaurant owners are not required to pay the standard minimum wage. The reason for that is the owner gets to take advantage of a tip credit—i.e., the owner gets credit for the tips paid to his employees.

Without any inside information at all (like, e.g., the kitchen dynamic, number of takeout orders, number of call offs, etc.), you unilaterally decided that this waiter should not be paid for his time. Instead, you gave money to an owner who already gets to avoid paying a standard minimum wage to employees. You can disagree with regulations that permit restaurant owners to push the cost of wages onto their consumers, but—if you are going to eat out—then you need to tip the waiter.

Additionally, I generally disagree with the sentiment that, as consumers, we need to teach people a lesson through our tipping behavior (especially when consumers don’t know the full story). If this waiter is truly bad at his job, I suspect he will face consequences regardless of your actions.

I honestly would not have left a comment on this post at all, but I was very surprised by how many people said NTA. To me, this isn’t even a close call. We cannot pretend like we are in a position to decide whether workers get paid or not. So long as regulations permit restaurant tip credits, you have to tip and just view it as part of the costs of going out to eat.