My experience in Japan is quite the opposite. A good place gets 3 stars because it's up to expectations, while any perceived slight from staff can easily get that down to 2 stars. Reviews of 4 stars or more from locals tend to correspond to some special experience.
Yes! Great point. Japan seems to be the only place where people actually rate sensibly.
Which, of course it is. There's a reason we're going back there, again, next week.