Japan bashing is popular. Looking at the data since QE started:
Real per capita GDP has risen 1.4% a year and yet prices have been constant.
I’m not sure why any one inflation target (positive or negative) is better than any other ((Woodford chapter 7 argues a target that tends to zero is optimal or a target that has expectations of inflation tending to zero is optimal.)). In any case, the level of the target is of second order importance to having stable inflation (and thus stable inflation expectations and thus having a target). The costs of discretion are much larger than the costs of minimal inflation (or deflation).