I had exactly the same observations while spending a month in Ghana.
There is no place on earth in which black people are as free and prosperous as they are in the US. Certainly no place in Africa.
GHANA? Oh my.
Yes, American blacks KNOW, I think, that Africa is ONLY a place to be FROM a long, long time ago. The stupids who rant and rave against the USA are just angry, frustrated and out to make everyone else as miserable as they are. Those stupids exist in every culture, race and faith.
They ALL find SOME reason to whine. That is who they are.