Talking about human rights in Africa is par for the course in US-Africa relations. I am not sure why the US thinks this approach will yield changes, I am sure they know it doesn't but that for the domestic audience it is very necessary. Many Africans also believe it's quite hypocritical that these statements are not made writ large for the Arab and Muslim allies of the US who are far worse on issues such as gay rights compared to countries like Kenya. There are even gay advocacy groups in countries like Kenya, Zimbabwe where the laws are tough on those issues. The fact that everyone says the US is playing catch up in Africa compared to China and yet this became the headline from this trip says it all. As for countries like Ethiopia we know that they are a close US ally and people like Jendayi Frazier among others cultivated that relationship strongly. Those issues and concerns will be raised as matter of deflecting domestic criticism but the US knows that it's not actually going to press the issue, Susan Rice has a record of defending some of these strongman and when the French wanted to get outright condemnation of Rwanda/Uganda sponsored M23 she was staunchly against it. Terrorism concerns in East Africa are above any commitment to human rights issues for the US. China prioritized economic ties and got a stronger foothold than anyone, i am sure with development these other issues will start to take prominence but in its absence people will view them as a sideshow.