Comment by pyrale

I assume the point is that what make them acknowledge and repent from what they did is that they lost the war.

Many massacres and genocides are "owner-less" and obscured by history. To give a few exemple, you might find, but the trail of tears is not as front-and-center in US' history teaching as the holocaust is in German history teaching.

You'll find similar situations for all colonial powers who didn't get dismantled and forced to accept their wrongs after losing a war. You may even go as far as to say that Germany is the outlier here.