Africa's citizens are in a similar situation
Iraq was attacked because it was ruled by a mad tyrant who supposedly has unconventional weapons, and there were no other ways of dealing with him other than war. Iraq was not attacked to make the Iraqies' situation any better - that will be just a by-product, if it indeed happens.

Africa is also a big-ass place, with hundreds of millions of people living inside it. It is hardly a good place to assault, for no reason other than 'to make things better' for those living there. If there's something Africa has had enough of, its war and killing.