In 2016, and through the first quarter of 2017, at the peak of the ponzi schemes frenzy that caught Nigeria (did you hear of MMM and the likes?), some friends asked me to create a similar platform for peer-to-peer donations for them. They wanted a matrix scheme with themselves at the top; they'd later take the site down suddenly after making much money; whoever came in last or invested much would be wrecked. I refused taking the job, and some other developer friends declined similar requests. I know some that took such jobs. So there are the dishonest ones, and there are the genuine ones.
While there are scammers raising the country's flag everywhere, I am certain many are not Nigerians. As Chimamanda Adichie said, the problem with stereotypes is not that they are false, but that they are only half the truth.