One bizarre consequence of zero rating limitations is that in Angola people started attaching pirated content to Wikipedia articles to create free filesharing. http://motherboard.vice.com/read/wikipedia-zero-facebook-fre...
It's impossible to overstate just how bad it would be to allow Facebook to define what is and isn't "the internet" for billions of people. I'm continuously stunned that anyone would defend their efforts in this area.
Can you think of a way to provide internet to everyone in the world that wouldn't involve a powerful entity who's intentions worry you? Maybe distributing mesh networking tech? Well, that would have to be developed, manufactured, and distributed, AND maintained. Who's going to do that? A charity? A consortium of charities?