This is my opinion (for what it's worth)...
There is a LOT of paganism/witchcraft and occult over in Africa.....
The country is cursed by it (G-d's word does not lie)...generations are cursed because of it....
Things would turn around over there if everyone would repent. (the hunger, poverty, etc)...
People have a rebellious spirit in them...until they repent....they carry anger, murder, idolatry, revenge, violence, etc...
That is why they can not forgive...because they need to repent and TURN from their wicked ways....and truly follow G-d.
Why do you think so many voted for Obama?
They are blind and they cannot see...because of their rebellion.
That is my 2 cents.
Why can't black people forgive white people for slavery and love America?
The explanation is simple. Most black America haters are the either leftist or poor or both. Both do not love to be responsible for their own lives and thus put themselves into the position of the eternal victim of slavery. Thus no one dares to tell them to get forward and make their lives and be responsible.
You can mostly see that successful blacks are patriotic, while the losers hate America and especially the whites and Asians.