You are entirely wrong in your assumptions. French is, indeed, a lingua franca in Western Africa, and is spoken widely from Côte d'Ivoire to Morocco by something close to 120 million people. A better question would be why it didn't completely displace local languages (Wolof, Arabic, etc.) as happened in Spanish colonies.

Also, Quebec definitely uses French. English is widely spoken because of the proximity with English-speaking regions of Canada and the US, but French is the mother tongue of most nonetheless.