They say if you can’t afford to tip, you can’t afford to eat out.
Makes sense, but it's funny how they never say if you can't afford to pay a living wage, you can't afford to run a business, isn't it?
In a sense, we sort of have a comparable setup in the UK for lots of businesses and employees - not just in the service industries (a PP mentioned Sainsburys adding an extra 15% to your total) - but it's done more subtly:
US: Has no nationwide minimum wage. Restaurant pays waitress too little to live on, so customers are expected individually to subsidise their employer's business by paying extra to top up her earnings to a living wage.
UK: Does have a nationwide minimum wage, but it's not a living wage - Supermarket pays checkout operator NMW (or pennies more) which is too little for her family to live on, so the taxpayer is expected corporately to subsidise their employer's business by paying tax credits to top up her earnings to a living wage.
Of course, this is now being phased out in favour of UC....