Most countries in Sub Saharan Africa, where Bantus live, get regular rainfall. This is why places poorer than Somalia in per capital terms like Burundi and Malawi don't have massive famines. They also don't have an imported, violent, millenarian ideology in control of a third of their countries including all the valuable agricultural land. Somalia is a naturally poor country, with huge religious and societal problems. Most Bantu countries are well watered and lack strong religious ideology, factors which mitigate to some extent their huge societal problems.