I'm not a fan of tipping either, but because the convention is clear and essentially universal, the waiter has a completely reasonable expectation that you will

I'm not a fan of tipping either, but because the convention is clear and essentially universal, the waiter has a completely reasonable expectation that you will tip unless there is a problem. If you go into the situation intending from the beginning not to follow this convention but receiving the benefits of it, then you are not acting in good faith. You are, through nonverbal communication, misleading the waiter. Consent should matter when two parties enter into a transaction, and it should be informed consent. If you think what you're doing right now meets that standard, then next time try telling the waiter at the beginning that there will be no tip, and see if it makes a difference.