Why do the Americans portray Africa as a giant slum inhabited by poverty ridden blacks?

I just returned from Kenya, Africa and actually did not see anything like that (I’m still aware that there is a lot of poverty elsewhere than where I traveled). I traveled from Senegal to Mali, and then flew to Kenya. People were really well dressed, clean in appearance, and the homes were very beautiful and large. In a sense, I'm kind of irritated that Americans are led to believe that Africans live horribly. I've learned from my experience that there is extreme poverty and extreme wealthy people in all nations. And oh my God, the people are damn beautiful in Africa. I was once told by some black American guy to not call black people "Africans" because they don't relate to them. I actually believe the black Americans who don't want to be referred to as African-Americans are just ashamed of their heritage. If those individuals were to visit Africa, as I did, their opinions of Africa would quickly change. Africa is home to a very diverse collection of people. It takes a novel to describe the beauty of Africa.