More to the point, the Paris attack struck close to home. The victims were journalists and journalists write the news. The terrorists hit a major Western city like the ones where the political leaders and opinion-makers live. The victims were aggressively secular. In marching for the victims, the famous and powerful were marching for themselves and their own.
Which does not apply to the victims in Nairobi and northern Nigeria. They were black Africans, not white Europeans; students, not journalists; living in the developing world, not Europe; and Christian, not modern and secular. No high official is going to fly to east Africa and march for them. The Kenyan and Nigerian victims are not their people.
They are ours. If someone could measure the amount of time American Christians spent reading about the three attacks, and the depth of of our emotional reaction, he would almost certainly find our time and emotional investment nearly as tilted to Paris as the secular Americans’. The more successful in the world, say in academia and publishing, the more this will be true. As a test, ask yourself what details of the Nigerian massacre you remember, compared with how much you remember of the Charlie Hebdo attacks. I remember a lot about the Nigerian massacre, but only because I read about it while writing this. Western journalists, even anti-Christian ones, are “our” people, Africa’s Christians a little less so.