We aren't.Why on earth are we apologising for something that happened before even our great-grandfathers were alive? What is the flipping point? In 50 years time do we expect the 2050 generation of Germans to start apologising for WW1?
The problem is that as soon as you apologise for something you're are infering some level of guilt, which then equals 'claims'. No one alive today is guilty in any way for the appalling practices of 150+ years ago. Also no one alive today can claim to be effected because a distant ancester was a slave. Where do you stop? I want an apology and compo from Italy because some distant ancestor was killed by the Romans in an invasion?
So again, what is the point?