I realize that pagan practices are abhorrent wherever they are practiced. Even Europe was not always Christian, for that matter.
But once the Gospel was preached to them, they (as a whole) accepted it.
To be clear, I wasn't saying that all black people are of bad will, or will necessarily reject the Gospel. On the contrary, it is the duty of those countries and peoples with the Faith to spread that Faith to those who still live in darkness. I did mention in my original post that Abp. Lefebvre made converts in Africa. The converts were fervent and were probably better Catholics than a lot of trad Catholics we see today.
Your statement about the polite Ethiopians mirrors the oft-quoted fact that converted Jєωs make the best Catholics. Both are true. The problem is that they are a minority (pardon the pun). As a GROUP, the Jєωs rejected, and still reject, God and His Christ.
Regarding Africa -- If we claim they don't live in darkness spiritually, we will end up in the multicultural camp saying things like, "All cultures are equal. We need to learn from those African tribes! Their customs can enrich us." whereas we know that their culture is based on paganism and darkness, and ought to be destroyed in favor of a higher, Christian culture.
When it comes down to it, it's the same Original Sin that we're all afflicted with. It just afflicts different people in different ways.