Your argument is moronic.
By your 'logic'?
You could say that it is good that a child was sexually molested, hundreds of times because it 'made them mentally stronger'?
Or it is good that WW2 happened (and 40 million people died) because of all the technological innovations that came from it.
Or it caused the UN to be created?
Or it accelerated the end of colonialization.
It is IMPOSSIBLE for you to prove that every, 'black' American would not have made it here on their own - without slavery.
Okay...show us all a link that proves with 100% certainty that every, 'black' American presently in America - would not be here were it not for slavery?
If you cannot - your entire point is nonsense.
The logic is straightforward. For blacks who think it is good that they live in the U.S. rather than in Africa, then they have to consider the slavery that made it possible to be good too. Otherwise, the vast majority of them wouldn't be here.
As for WW II, it was bad that it happened. It was bad that FDR knew the Japanese were going to attack but did nothing. To treasonously sucker the American people into supporting war. It was bad that the U.S It was bad that the U.S. decided to back the filthy, murderous piece of shit Stalin rather than the hero Hitler. Do you need more?