Tipping sounds like a stupid way to incentivize good service, because the best waiters are the ones who don't pester you every 5 seconds, asking if everything is ok.
But then why would you tip them an extra, if all they have to do is interact with you as little as possible?

It's a catch 22, and the only answer is trays on the back of trained dogs, which you can "tip" with dog biscuits.