It depends on how big a STEM facility should be to qualify for a reasonable excuse.
Even here in South-Eastern Nigeria, we have the Scientific Equipment Development Institute (SEDI). Not big though. And some other cool STEM facilities in Nigeria. Maybe not too big for a good STEM excuse.
Oh yeah! The Dangote oil refinery; which is meant to be the largest in the African continent; should be ready by 2019 (all things being equal). Maybe that could suffice for a STEM excuse in the future; who knows? :D
I don't know. To be discussed :)