Apartheid in South Africa, Robert Mugabe in Zimbabwe, Idi Amin in Uganda, the Tutsi genocide in Rwanda, Mobuto in Zaire et cetera were all hot topics at their time, at least once the magnitude of the events became clear. In contrast, the current anarchy in Somalia and the ongoing conflict in Nigeria goes almost completely unreported. Even the Nigerian Civil War back in the 60s got more coverage than the war in the same country today. Our focus has simply shifted to other more pressing events.
Besides, the amount of attention media devotes to an event is contingent on how much information and material it can get on it. It is easy to report on events in France - it is almost impossible to do the same in inland Nigeria. There aren't exactly legions of local bloggers posting video clips on the internet, and a reporter going into the region would likely not come out again.