So, its a thing among migrants? Is there any particular reason you can think of? Apologies, I only know some of the broad strokes of Nigerian and/or West African history.
This is in my honest opinion based on my personal experience so it's going to seem very narrow. But I ask children of immigrants to chime in please. (/disclaimer)
Some Nigerians that emigrate to places like Canada and the USA, 10 or more years ago tend to be about hustling through education either gained from back home or abroad. The ones that work really hard to live a very comfortable life or get lucky then to build a relatively comforatable lifestyle where bills can be paid without too much worry. They can be very prideful of what they have achieved and will worry about the politcal troubles that are seen back in Nigeria. Overtime, that worry of kinsmen can turn to contempt due to stereotypes they have adopted living abroad ("Nigerians are scam artists/419ers, but you 'Sola Akinyele' aren't like them. You work hard"), amongst other factors. Soon enough they may associate less and less within people within their inherited community and soon enough enter this weird state of assimilation, while still claiming multiple aspects of their culture quietly.
To hear some of the vitriol that has come out of the mouths of these people when addressing other Nigerians plights and situations, is sad and terrible.