Don't count on it. Wouldn't you think if it wasn't working there would have been an uprising by now? The fact of the matter is that it does work as is, and you can make good money as a server if you are good at what you do. Of course there are the cheapskates out there that feel they are making some sort of "statement" by not tipping but then there are the grounded people that realize these people rely on these tips. 15% isn't much for decent service where you get your order taken, drinks refilled in a timely manner but it is the fact that servers want to please the customers beyond the job description that make higher tipping worth it.