The OP isn't just bush-talking, it's a fact that the demand and use of cryptocurrency is on the rise in Africa. I belong to several cryptocurrency groups populated by Africans and I know how daily increase we have in members flooding these groups. Although that number dropped middle of 2018, it has picked up again now. And of course, demand sets the pace for price determination and increase. The more people use cryptocurrency, the higher price goes. That was what happened in 2017 where almost all the cryptos recorded ATH.
Dont pay attention to him, he just needs to do his research well to really know the ration of Africans involvement in crypto, look at this project, Africunia Cash, is it not an African project based in United Kingdom.
Take Nigeria for example too, I learnt that they rate at which they adopted cryptocurrency in 2017/2018 was so high that their Central Bank started campaigning against it before they get out of hand and when it comes to investment, they also have a large part too though can never be compared to the one from America and Europe. So, he should better do his research right before querying the op and also learn from your write-up.