So, what is your point? That one country got off cheaply with two nuclear holocausts in 1945 while another is stepping up by paying reparations 70 years later?

Legally and otherwise punishment is a form of payment that individuals, societies or even bunches of countries exacts against wrongs committed. It doesn't matter who decides what form it takes. 

Whether they've paid nearly enough is not something I'll get into here. My point is that what they have paid is not nothing or even insignificant.