I think the deal is that these Zuck-privileged sites don't count against the phone user's mobile data usage, which is otherwise going to be 1 zillion rupees per megabyte.
[1],
[2]
So the problem is the mobile carriers not the Facebooks, and they are the ones who make it "impossible" to make the whole of the internet free. But in offering to pay the mobile carriers something in compensation (which he must be), he's kind of supporting the problem.