Why can't it be both?
The only way for both sides to profit (over the long run) is for either country to do the job it can do the most efficiently, i.e. comparative advantage. In practice, that's a real tough concept for people to come to terms with. People want to have their cake and eat it too.
Who would want to create the exact same jobs that fit the needs of a labour market in the poorest region of the world in the US? What's the point of having someone in the US who went through at least 12 years of education to manually select pixels on a screen?
Getting those jobs to people in Nairobi is good for them because it lifts them out of dangerous and hazardous jobs, and it would be a horrible place to work at in a developed country.
The state of affairs may have improved in the interim