I have no idea either why people conflate. At the least, North Africa and sub-Saharan Africa should never be conflated

North Africa is part of the Middle East culturally, politically, and religiously. The Arab Spring was largely North African in focus, before the Syrian civil war preoccupied attention. Democracy faces a major hurdle even in the stablest nations there. Authoritarian traditions stretch back +2,000 years.

Sub Saharan Africa is far less influenced by ME Islamist traditions and far more aligned to a similar postcolonial timeline as South Asia and caudillo era Latin America. Despite some truly vast cities, most folks remain rural. This is also the region that rightly or wrongly, is seen as both a wild National Geographic idyll, or conversely one threatened by overpopulation. Crucial point. Democracy is the general prevailing ideology here, even if more honored in the breach.

And even this summarization grossly oversimplifies. Shameless plug, it's fascinating to read about ECOAS and the African Union