Not quite, look at Germany, Germany has faced up to it's responsibilities with regard to the holocaust, it is because of this Germany can move on and build a future.
Turkey has never acknowledged the Armenian genocide and on March 23 the Prime Minister of Turkey will pay his respects to the organiser of the genocide (Talaat Bey) it was the world's indifference to the Armenian suffering that led Hitler to say "who talks of the Armenians now?" the rest is, well, "history".
Take the rape of Nanking, the Japanese don't acknowledge the atrocities they committed so much so that, again, ministers of state pay their respects at monuments that commemorate war criminals.
These things matter because the people who suffered for it mattered, their antecendents still matter and it still matters to them.
Take Bible John, his victims, long since dead (murdered), himself long since dead, should they not have dug him up to say for certain he did it?
What good did it do?
It brought closure.
You hve to identify the injustices, you have to identify the wrongs on all sides (like apologising for slavery) with the gesture of an apology, with the notion of acknowledgement you can start to bring about reconciliation.
Easier said than done.
The idea of a Maoist style year zero, is not the solution.
Mary Shelley wrote "the best place to start a story is at the beginning, but like all beginnings, it is based in what has gone before."