Earlier quoted context omitted.
Yeah ... but a huge fraction of Whatsapp users (in India & Africa especially) use $100 (or less) phones....
Thousands of corporations have survived without having to worry about markets that don't have disposable income. You don't see Apple hurting because they aren't successful in the poorest areas in the world. It may sound cruel, but is it crueler than saying "Since you can't afford to pay, just give us access to your emails and private messages"?
Facebook has a different business model and a different mission than those companies.