I don't really see it as adoption, it's more like enabling the Nigerians to get some BTC in an easier manner. A little but sweet development for BTC in your country, and I'm happy to know you've now got an option to purchase and sell in a physical way.
Lol, your perspective tho. However, it is clearly adoption because if it is not being adopted by the people in the country, why then would someone bring a Bitcoin ATM?
Well, I believe that an analysis was done and observing that people are moving into cryptocurrency, hence the step was taken.