As someone who lives in a country where tipping isn't mandatory, and where it's illegal to pay service staff less than minimum wage, the American system has never made any sense to me whatsoever.
Over here if you've been provided with a service that you believe warrants a tip, and you currently are able to afford to tip, then you leave a tip. If you don't leave a tip you're at least sure that the staff member is being paid a relatively fair wage.
This also means staff aren't overly friendly which always bothers me when I'm in the states, but perhaps that's because I'm a grumpy Englishman.
It's a step in the right direction in my opinion.