The French government.
As for expanding into "3rd world" markets, the average monthly Senegalese salary appears to be 139€. And this is a country considered to be doing well in the region.
They're expanding and offering "free internet" because there's nowhere else to go. Because even though it's poor now, there's growth, and they want to be established and deeply encroached when those markets will become worth it. Because they believe better and wider internet coverage will spur even more growth.
The only reason these companies can exist and be worth anything today is because of all the groundwork and investment that has been and continuously is made.