In my company, our deployment engineers, who usually are on very remote places with bad and unreliable internet, rely on WhatsApp. I'm not saying this is the best practice, but this is simply the way Brazil works right now. Even the mobile phone companies offer plans with free WhatsApp connection, because that is what most people here care about. Another example: In Brazil, 9 in 10 doctors use WhatsApp to talk to patients (http://www.cityam.com/230372/digital-health-wearables-and-ap...).
To disregard all the people and businesses that rely on WhatsApp for whatever reason is unbelievable. But this is not without precedent, once another Brazilian judge blocked YouTube for a whole day because it refused to take down a celebrity video.
This says a lot about the over-sized, inefficient, and stupid state we have, always meddling and intervening.