Again, for the umpteenth time, nobody is arguing that slavery isn't evil. What we are trying to say is that whatever bad things happened to people's ancestors, if the descendants of the ancestors are living good lives, it's pointless to complain about bad things happening to their ancestors.
I agree. It is all about context. Truth to tell it wasn't that long ago that people used to brag about "how far we have came since our family moved to America."
One benefit alone was so enormous back then it was practically unheard of in "the olde countries",and that was coming here dirt poor and being able to work your way into owning land you could farm or run a business on. No more having to pay a "lord" for permission to use his land to earn a living.
I am sure if you mentioned this to most people of today,they would say "huh?". They accept it as truth without ever even having thought about what it meant/means.
And what it REALLY means is "freedom". Everything flows from there. You can never accomplish anything unless you have the freedom and give it a try.