Take a look at africa and poorer countries - the majority of money transfers is done over mobile services such as sms rather than internet
Make sense... however, SMS is an obsolete method of communication, and sooner or later, all people will migrate to the internet, just like a landline, telegraph, fax, etc.
I understand if they want to acquire African users with SMS. Still, it might not be worth the effort if you spent resources developing on top of a sinking technology since it has a limited lifetime.