Or maybe it sees little usage inside of your own country? Even when most people use other messaging platforms, I see it used as the family/iphone-possessing-close-friends channel of choice, since it transparently replaces SMS.
While SMS fallback is handled brilliantly by iMessage, as soon as people are using it as more than a glorified sms client (group chat, file transfer...) and/or are really concerned about end-to-end encryption, the limitations of SMS/MMS start to become a dealbreaker.