Appointments in Africa are politically based and have nothing to do with competence, experience or education in the appropriate discipline. The replacement will be more of the same.
Another pre-requisite (especially in Nigeria) is to be profoundly venal and corrupt. Anybody with an anti-corruption agenda gets the cold-shoulder from other power-brokers who see a threat to their own cash-flow.
The key to climbing the career ladder in Nigeria is to be slightly less corrupt than the people above you, and only a bit more corrupt than those immediately below you. Rock the equilibrium too much (as Stella did) and you get undermined and pushed out.