Tell me about it.
The continent (let's not even talk about the countries comprising it) has been culturally fractured for centuries - and that's not about to change any time soon. Africa simply cannot be united in the way that Europe or America are united. Tribal rivalry is a fact of African life. Take away tribalism, and you take away an integral part of African identity. Yes, it causes major problems in politics, but it's the way it has always been. It will
not change.
Hmm.... WWI and II anyone? Europe had been 'culturally factured for centuries' until after WWII on a scale that is incomparable in Africa. Just a reminder than less than 100 years ago, Europe went through two major wars in which tens of millions of people died. Still today there is a European Union functioning rather well, but of course cultural differences are still there and will remain.
The idea that Africa is fundamentally more divided than Europe is crap IMO. If anything there is a stronger natural continental identity there than anywhere else in the world. This is not to say that tribal differences are not a fundamental aspect of the relationships between people (and I agree it is not about to change miraculously), but the question of identity is a mix of tribal, national, regional, religious, and continental. The point here is that national identity as we understand them in Europe or America is rather weak there, mostly due to the fact the countries are quite 'new' (less than 50 years of independence for most) and that the borders were drawn up by colonial powers irrespective of existing cultural identities at the time.
This idea of 'United States of Africa' or Pan-africanism is, as some have pointed out, not only not Bono's idea, but an enduring and very important movement among African politicians, intellectuals, artists and so forth, and has been for decades. When most African countries became independent in the 1960s this was a widespread ideal, and there was very serious discussions among the emerging leaders to have much larger political entities than the ones we know today. Just look at the flag of West African countries, they all look very similar and that is not a coincidence.
Now of course this US of Africa did not work then, because of rivalries (many of them tribal, very true), and we are nowhere near being able to achieve something like that today. But no one (including Bono) is talking about making Africa one country, but rather try to re-enforce pan-African identity (which, I argue, already exists and is getting stronger) and continental institutions. I do not think Africa is on the brink of becoming like the EU, but I do think that it is a very sensible ideal to aspire to and move towards.
I am not saying this just to defend Bono because I have no problem disagreeing with him, but those who think he is talking nonsense and doesn't know what he is talking are the ones who need to get better informed and should go read up about African history or better, go there to see for themselves and they will see that this ideal is in fact shared by many people on the continent.