Your point has merit, but I'd make a slightly different argument, focusing on the victims rather than on the criminals. Reparations are in order as long as anyone is still alive who was directly affected by these war crimes.
And those directly affected would be the people who were there at the time, and their children.
I include the children because what has happened to your parents, good or bad, greatly affects you. This is less so with grandchildren, and much less so with generations thereafter.
I agree the victims should be made whole. Government should not be exempt from something that would be a prosecutable crime if you or I did it.
The Nazi murders are fine examples.
The 8th air force killed massive numbers of people, that is a legitimate act of war.
It has never been a legitimate act of war to round up civilians and murder them. It has never been legitimate to make groups of woman strip naked, stand by a ditch and shoot them one by one.
It has never been legitimate to murder POWs. The Germans and Japs did that wholesale.
But the question is who owes the victims something? Germany ceased to exist. The government today has nothing to do with Nazi crimes. What you would have is a nation and government that was not involved, taxing people who were not involved to pay those reparations.
The only thing the Germans owe the Greeks today is from the German central bank which forced at gunpoint the Greek central bank to give them immense loans. That should be paid back with interest.
But I cannot see taxing my 50 year old German friends, so that a government that had nothing to do with Nazi crimes, can give money to someone who never met a Nazi. That’s just nuts to me.
Greece and Germany have modern choice to make. The Germans can cut them off. The Greeks may leave NATO and invite the Russians in. Of Germany may carry them for geopolitical reasons.
Its a European problem.