From what I understand, it's a tradeoff between good service and having to do rudimentary math OR variable service and not doing any math (math is a lame excuse IMO). I don't know about Australia or Japan, but I can tell you first hand the restaurant service in much of Europe can often be indifferent at best. Surly servers are not at all uncommon.
Though folks in bargain restaurants or counter service often work hard and make little, that's not the case for most servers. The minimum wage angle is mostly a red herring. I was a waiter in a mid-high end restaurant years ago, did my very best to make every diners experience as nice as possible, and made money hand over fist - easily as much as a degreed entry level engineer (from personal experience). Servers in middle and higher end restaurants make far more than minimum wage despite their hourly pay. They wouldn't do those jobs if the pay wasn't worth it.
But it's a debate with no end, or right answer. However, even if restaurants choose to build in tips as some major US markets have begun to implement, bad service will still have the same effect on the restaurant (complaints to management, or just never going back) - but the servers won't feel the pinch as quickly or directly. Since most people are afraid to complain, it could be harder for restaurant owners to catch on to bad servers.
